From c6a46604e30f8d26ceef66cc1c816cc694488737 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Thu, 16 Jun 2016 23:38:06 +0200
Subject: [PATCH 01/30] To allow reproducible output: * honour
 SOURCE_DATE_EPOCH for timestamps in PS and PDF files.   See
 https://reproducible-builds.org/specs/source-date-epoch/ * get keys sorted so
 that hatchPatterns, images and markers are included with   a reproducible
 order in the PDF file. See https://reproducible-builds.org/

---
 lib/matplotlib/backends/backend_pdf.py | 45 +++++++++++++++++++++-----
 lib/matplotlib/backends/backend_ps.py  |  9 +++++-
 2 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
index 21719273c423..a166c9a8f1aa 100644
--- a/lib/matplotlib/backends/backend_pdf.py
+++ b/lib/matplotlib/backends/backend_pdf.py
@@ -17,6 +17,7 @@
 import time
 import warnings
 import zlib
+import collections
 from io import BytesIO
 from functools import total_ordering
 
@@ -24,7 +25,7 @@
 from six import unichr
 
 
-from datetime import datetime
+from datetime import datetime, tzinfo, timedelta
 from math import ceil, cos, floor, pi, sin
 
 import matplotlib
@@ -135,6 +136,20 @@ def _string_escape(match):
     assert False
 
 
+# tzinfo class for UTC
+class UTCtimezone(tzinfo):
+    """UTC timezone"""
+
+    def utcoffset(self, dt):
+        return timedelta(0)
+
+    def tzname(self, dt):
+        return "UTC"
+
+    def dst(self, dt):
+        return timedelta(0)
+
+
 def pdfRepr(obj):
     """Map Python objects to PDF syntax."""
 
@@ -202,10 +217,14 @@ def pdfRepr(obj):
     # A date.
     elif isinstance(obj, datetime):
         r = obj.strftime('D:%Y%m%d%H%M%S')
-        if time.daylight:
-            z = time.altzone
+        z = obj.utcoffset()
+        if z is not None:
+            z = z.seconds
         else:
-            z = time.timezone
+            if time.daylight:
+                z = time.altzone
+            else:
+                z = time.timezone
         if z == 0:
             r += 'Z'
         elif z < 0:
@@ -468,10 +487,19 @@ def __init__(self, filename):
         self.writeObject(self.rootObject, root)
 
         revision = ''
+        # get source date from SOURCE_DATE_EPOCH, if set
+        # See https://reproducible-builds.org/specs/source-date-epoch/
+        source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
+        if source_date_epoch:
+            source_date = datetime.utcfromtimestamp(int(source_date_epoch))
+            source_date = source_date.replace(tzinfo=UTCtimezone())
+        else:
+            source_date = datetime.today()
+
         self.infoDict = {
             'Creator': 'matplotlib %s, http://matplotlib.org' % __version__,
             'Producer': 'matplotlib pdf backend%s' % revision,
-            'CreationDate': datetime.today()
+            'CreationDate': source_date
             }
 
         self.fontNames = {}     # maps filenames to internal font names
@@ -483,14 +511,15 @@ def __init__(self, filename):
 
         self.alphaStates = {}   # maps alpha values to graphics state objects
         self.nextAlphaState = 1
-        self.hatchPatterns = {}
+        # reproducible writeHatches needs an ordered dict:
+        self.hatchPatterns = collections.OrderedDict()
         self.nextHatch = 1
         self.gouraudTriangles = []
 
-        self._images = {}
+        self._images = collections.OrderedDict()   # reproducible writeImages
         self.nextImage = 1
 
-        self.markers = {}
+        self.markers = collections.OrderedDict()   # reproducible writeMarkers
         self.multi_byte_charprocs = {}
 
         self.paths = []
diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index b5d284cfffbd..76b43fcb47a4 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -1087,7 +1087,14 @@ def print_figure_impl():
             if title: print("%%Title: "+title, file=fh)
             print(("%%Creator: matplotlib version "
                          +__version__+", http://matplotlib.org/"), file=fh)
-            print("%%CreationDate: "+time.ctime(time.time()), file=fh)
+            # get source date from SOURCE_DATE_EPOCH, if set
+            # See https://reproducible-builds.org/specs/source-date-epoch/
+            source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
+            if source_date_epoch:
+                source_date = time.asctime(time.gmtime(int(source_date_epoch)))
+            else:
+                source_date = time.ctime()
+            print("%%CreationDate: "+source_date, file=fh)
             print("%%Orientation: " + orientation, file=fh)
             if not isEPSF: print("%%DocumentPaperSizes: "+papertype, file=fh)
             print("%%%%BoundingBox: %d %d %d %d" % bbox, file=fh)

From 4e477dc381172f145f1d28f322ee78d7a33f3624 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Sat, 18 Jun 2016 17:42:21 +0200
Subject: [PATCH 02/30] Reproducible PDF output: sort TTF characters

---
 lib/matplotlib/backends/backend_pdf.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
index a166c9a8f1aa..c6fe7c24a1f5 100644
--- a/lib/matplotlib/backends/backend_pdf.py
+++ b/lib/matplotlib/backends/backend_pdf.py
@@ -949,7 +949,8 @@ def get_char_width(charcode):
             rawcharprocs = ttconv.get_pdf_charprocs(
                 filename.encode(sys.getfilesystemencoding()), glyph_ids)
             charprocs = {}
-            for charname, stream in six.iteritems(rawcharprocs):
+            for charname in sorted(rawcharprocs):
+                stream = rawcharprocs[charname]
                 charprocDict = {'Length': len(stream)}
                 # The 2-byte characters are used as XObjects, so they
                 # need extra info in their dictionary

From 946ae4541ae5eaba015cf2a50ce82c511e524313 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Sat, 18 Jun 2016 17:58:24 +0200
Subject: [PATCH 03/30] Reproducible PDF output: sort fonts

---
 lib/matplotlib/backends/backend_pdf.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
index c6fe7c24a1f5..a15e13c3a612 100644
--- a/lib/matplotlib/backends/backend_pdf.py
+++ b/lib/matplotlib/backends/backend_pdf.py
@@ -669,7 +669,8 @@ def fontName(self, fontprop):
 
     def writeFonts(self):
         fonts = {}
-        for filename, Fx in six.iteritems(self.fontNames):
+        for filename in sorted(self.fontNames):
+            Fx = self.fontNames[filename]
             matplotlib.verbose.report('Embedding font %s' % filename, 'debug')
             if filename.endswith('.afm'):
                 # from pdf.use14corefonts

From 22f71a28271b6e849634f093564fef9dc22df706 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Sat, 18 Jun 2016 18:07:21 +0200
Subject: [PATCH 04/30] Tests for determinist PDF output: - SOURCE_DATE_EPOCH
 support - reproducible output

---
 lib/matplotlib/tests/test_backend_pdf.py | 131 +++++++++++++++++++++++
 1 file changed, 131 insertions(+)

diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
index 2feee6fb1238..e0a9a53546ad 100644
--- a/lib/matplotlib/tests/test_backend_pdf.py
+++ b/lib/matplotlib/tests/test_backend_pdf.py
@@ -109,6 +109,137 @@ def test_composite_image():
         assert len(pdf._file._images.keys()) == 2
 
 
+@cleanup
+def test_source_date_epoch():
+    # Test SOURCE_DATE_EPOCH support
+    try:
+        # save current value of SOURCE_DATE_EPOCH
+        sde = os.environ.pop('SOURCE_DATE_EPOCH',None)
+        fig = plt.figure()
+        ax = fig.add_subplot(1, 1, 1)
+        x = [1, 2, 3, 4, 5]
+        ax.plot(x, x)
+        os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+        with io.BytesIO() as pdf:
+            fig.savefig(pdf, format="pdf")
+            pdf.seek(0)
+            buff = pdf.read()
+            assert b"/CreationDate (D:20000101000000Z)" in buff
+        os.environ.pop('SOURCE_DATE_EPOCH',None)
+        with io.BytesIO() as pdf:
+            fig.savefig(pdf, format="pdf")
+            pdf.seek(0)
+            buff = pdf.read()
+            assert not b"/CreationDate (D:20000101000000Z)" in buff
+    finally:
+        # Restores SOURCE_DATE_EPOCH
+        if sde == None:
+            os.environ.pop('SOURCE_DATE_EPOCH',None)
+        else:
+            os.environ['SOURCE_DATE_EPOCH'] = sde
+
+
+def _test_determinism_save(filename, objects=''):
+    # save current value of SOURCE_DATE_EPOCH and set it
+    # to a constant value, so that time difference is not
+    # taken into account
+    sde = os.environ.pop('SOURCE_DATE_EPOCH',None)
+    os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+
+    fig = plt.figure()
+
+    if 'm' in objects:
+        # use different markers, to be recorded in the PdfFile object
+        ax1 = fig.add_subplot(1, 6, 1)
+        x = range(10)
+        ax1.plot(x, [1] * 10, marker=u'D')
+        ax1.plot(x, [2] * 10, marker=u'x')
+        ax1.plot(x, [3] * 10, marker=u'^')
+        ax1.plot(x, [4] * 10, marker=u'H')
+        ax1.plot(x, [5] * 10, marker=u'v')
+
+    if 'h' in objects:
+        # also use different hatch patterns
+        ax2 = fig.add_subplot(1, 6, 2)
+        bars = ax2.bar(range(1, 5), range(1, 5)) + \
+               ax2.bar(range(1, 5), [6] * 4, bottom=range(1, 5))
+        ax2.set_xticks([1.5, 2.5, 3.5, 4.5])
+
+        patterns = ('-', '+', 'x', '\\', '*', 'o', 'O', '.')
+        for bar, pattern in zip(bars, patterns):
+            bar.set_hatch(pattern)
+
+    if 'i' in objects:
+        # also use different images
+        A = [[1, 2, 3], [2, 3, 1], [3, 1, 2]]
+        fig.add_subplot(1, 6, 3).imshow(A, interpolation='nearest')
+        A = [[1, 3, 2], [1, 2, 3], [3, 1, 2]]
+        fig.add_subplot(1, 6, 4).imshow(A, interpolation='bilinear')
+        A = [[2, 3, 1], [1, 2, 3], [2, 1, 3]]
+        fig.add_subplot(1, 6, 5).imshow(A, interpolation='bicubic')
+
+    x=range(5)
+    fig.add_subplot(1, 6, 6).plot(x,x)
+
+    fig.savefig(filename, format="pdf")
+
+    # Restores SOURCE_DATE_EPOCH
+    if sde == None:
+        os.environ.pop('SOURCE_DATE_EPOCH',None)
+    else:
+        os.environ['SOURCE_DATE_EPOCH'] = sde
+
+
+def _test_determinism(objects=''):
+    import sys
+    from subprocess import check_call
+    from nose.tools import assert_equal
+    filename = 'determinism_O%s.pdf' % objects
+    plots = []
+    for i in range(3):
+        check_call([sys.executable, '-R', '-c',
+                    'import matplotlib; '
+                    'matplotlib.use("pdf"); '
+                    'from matplotlib.tests.test_backend_pdf '
+                    'import _test_determinism_save;'
+                    '_test_determinism_save(%r,%r)' % (filename,objects)])
+        with open(filename, 'rb') as fd:
+            plots.append(fd.read())
+        os.unlink(filename)
+    for p in plots[1:]:
+        assert_equal(p,plots[0])
+
+
+@cleanup
+def test_determinism_plain():
+    """Test for reproducible PDF output: simple figure"""
+    _test_determinism()
+
+
+@cleanup
+def test_determinism_images():
+    """Test for reproducible PDF output: figure with different images"""
+    _test_determinism('i')
+
+
+@cleanup
+def test_determinism_hatches():
+    """Test for reproducible PDF output: figure with different hatches"""
+    _test_determinism('h')
+
+
+@cleanup
+def test_determinism_markers():
+    """Test for reproducible PDF output: figure with different markers"""
+    _test_determinism('m')
+
+
+@cleanup
+def test_determinism_all():
+    """Test for reproducible PDF output"""
+    _test_determinism('mhi')
+
+
 @image_comparison(baseline_images=['hatching_legend'],
                   extensions=['pdf'])
 def test_hatching_legend():

From ad660d721f9adba1f716506de8b28e9695565583 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Mon, 27 Jun 2016 20:35:29 +0200
Subject: [PATCH 05/30] Share determinism test code for PS and PDF output.

---
 lib/matplotlib/testing/determinism.py    | 133 +++++++++++++++++++++++
 lib/matplotlib/tests/test_backend_pdf.py | 111 ++-----------------
 lib/matplotlib/tests/test_backend_ps.py  |  12 ++
 3 files changed, 153 insertions(+), 103 deletions(-)
 create mode 100644 lib/matplotlib/testing/determinism.py

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
new file mode 100644
index 000000000000..f32286d7803c
--- /dev/null
+++ b/lib/matplotlib/testing/determinism.py
@@ -0,0 +1,133 @@
+"""
+Provides utilities to test output reproducibility.
+"""
+
+import io
+import os
+
+from matplotlib import pyplot as plt
+
+
+def _test_determinism_save(filename, objects='mhi', format="pdf"):
+    # save current value of SOURCE_DATE_EPOCH and set it
+    # to a constant value, so that time difference is not
+    # taken into account
+    sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
+    os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+
+    fig = plt.figure()
+
+    if 'm' in objects:
+        # use different markers...
+        ax1 = fig.add_subplot(1, 6, 1)
+        x = range(10)
+        ax1.plot(x, [1] * 10, marker=u'D')
+        ax1.plot(x, [2] * 10, marker=u'x')
+        ax1.plot(x, [3] * 10, marker=u'^')
+        ax1.plot(x, [4] * 10, marker=u'H')
+        ax1.plot(x, [5] * 10, marker=u'v')
+
+    if 'h' in objects:
+        # also use different hatch patterns
+        ax2 = fig.add_subplot(1, 6, 2)
+        bars = ax2.bar(range(1, 5), range(1, 5)) + \
+            ax2.bar(range(1, 5), [6] * 4, bottom=range(1, 5))
+        ax2.set_xticks([1.5, 2.5, 3.5, 4.5])
+
+        patterns = ('-', '+', 'x', '\\', '*', 'o', 'O', '.')
+        for bar, pattern in zip(bars, patterns):
+            bar.set_hatch(pattern)
+
+    if 'i' in objects:
+        # also use different images
+        A = [[1, 2, 3], [2, 3, 1], [3, 1, 2]]
+        fig.add_subplot(1, 6, 3).imshow(A, interpolation='nearest')
+        A = [[1, 3, 2], [1, 2, 3], [3, 1, 2]]
+        fig.add_subplot(1, 6, 4).imshow(A, interpolation='bilinear')
+        A = [[2, 3, 1], [1, 2, 3], [2, 1, 3]]
+        fig.add_subplot(1, 6, 5).imshow(A, interpolation='bicubic')
+
+    x = range(5)
+    fig.add_subplot(1, 6, 6).plot(x, x)
+
+    fig.savefig(filename, format=format)
+
+    # Restores SOURCE_DATE_EPOCH
+    if sde is None:
+        os.environ.pop('SOURCE_DATE_EPOCH', None)
+    else:
+        os.environ['SOURCE_DATE_EPOCH'] = sde
+
+
+def _test_determinism(objects='mhi', format="pdf"):
+    """
+    Output three times the same graphs and checks that the outputs are exactly
+    the same.
+
+    Parameters
+    ----------
+    objects : str
+        contains characters corresponding to objects to be included in the test
+        document: 'm' for markers, 'h' for hatch patterns, 'i' for images. The
+        default value is "mhi", so that the test includes all these objects.
+    format : str
+        format string. The default value is "pdf".
+    """
+    import sys
+    from subprocess import check_call
+    from nose.tools import assert_equal
+    filename = 'determinism_O%s.%s' % (objects, format)
+    plots = []
+    for i in range(3):
+        check_call([sys.executable, '-R', '-c',
+                    'import matplotlib; '
+                    'matplotlib.use(%r); '
+                    'from matplotlib.testing.determinism '
+                    'import _test_determinism_save;'
+                    '_test_determinism_save(%r,%r,%r)'
+                    % (format, filename, objects, format)])
+        with open(filename, 'rb') as fd:
+            plots.append(fd.read())
+        os.unlink(filename)
+    for p in plots[1:]:
+        assert_equal(p, plots[0])
+
+def _test_source_date_epoch(format, string):
+    """
+    Test SOURCE_DATE_EPOCH support. Output a document with the envionment
+    variable SOURCE_DATE_EPOCH set to 2000-01-01 00:00 UTC and check that the
+    document contains the timestamp that corresponds to this date (given as an
+    argument).
+
+    Parameters
+    ----------
+    format : str
+        format string, such as "pdf".
+    string : str
+        timestamp string for 2000-01-01 00:00 UTC.
+    """
+    try:
+        # save current value of SOURCE_DATE_EPOCH
+        sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
+        fig = plt.figure()
+        ax = fig.add_subplot(1, 1, 1)
+        x = [1, 2, 3, 4, 5]
+        ax.plot(x, x)
+        os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+        with io.BytesIO() as output:
+            fig.savefig(output, format=format)
+            output.seek(0)
+            buff = output.read()
+            assert string in buff
+        os.environ.pop('SOURCE_DATE_EPOCH', None)
+        with io.BytesIO() as output:
+            fig.savefig(output, format=format)
+            output.seek(0)
+            buff = output.read()
+            assert string not in buff
+    finally:
+        # Restores SOURCE_DATE_EPOCH
+        if sde is None:
+            os.environ.pop('SOURCE_DATE_EPOCH', None)
+        else:
+            os.environ['SOURCE_DATE_EPOCH'] = sde
diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
index e0a9a53546ad..4b038a3e685f 100644
--- a/lib/matplotlib/tests/test_backend_pdf.py
+++ b/lib/matplotlib/tests/test_backend_pdf.py
@@ -12,6 +12,7 @@
 from matplotlib import cm, rcParams
 from matplotlib.backends.backend_pdf import PdfPages
 from matplotlib import pyplot as plt
+from matplotlib.testing.determinism import _test_source_date_epoch, _test_determinism
 from matplotlib.testing.decorators import (image_comparison, knownfailureif,
                                            cleanup)
 
@@ -111,133 +112,37 @@ def test_composite_image():
 
 @cleanup
 def test_source_date_epoch():
-    # Test SOURCE_DATE_EPOCH support
-    try:
-        # save current value of SOURCE_DATE_EPOCH
-        sde = os.environ.pop('SOURCE_DATE_EPOCH',None)
-        fig = plt.figure()
-        ax = fig.add_subplot(1, 1, 1)
-        x = [1, 2, 3, 4, 5]
-        ax.plot(x, x)
-        os.environ['SOURCE_DATE_EPOCH'] = "946684800"
-        with io.BytesIO() as pdf:
-            fig.savefig(pdf, format="pdf")
-            pdf.seek(0)
-            buff = pdf.read()
-            assert b"/CreationDate (D:20000101000000Z)" in buff
-        os.environ.pop('SOURCE_DATE_EPOCH',None)
-        with io.BytesIO() as pdf:
-            fig.savefig(pdf, format="pdf")
-            pdf.seek(0)
-            buff = pdf.read()
-            assert not b"/CreationDate (D:20000101000000Z)" in buff
-    finally:
-        # Restores SOURCE_DATE_EPOCH
-        if sde == None:
-            os.environ.pop('SOURCE_DATE_EPOCH',None)
-        else:
-            os.environ['SOURCE_DATE_EPOCH'] = sde
-
-
-def _test_determinism_save(filename, objects=''):
-    # save current value of SOURCE_DATE_EPOCH and set it
-    # to a constant value, so that time difference is not
-    # taken into account
-    sde = os.environ.pop('SOURCE_DATE_EPOCH',None)
-    os.environ['SOURCE_DATE_EPOCH'] = "946684800"
-
-    fig = plt.figure()
-
-    if 'm' in objects:
-        # use different markers, to be recorded in the PdfFile object
-        ax1 = fig.add_subplot(1, 6, 1)
-        x = range(10)
-        ax1.plot(x, [1] * 10, marker=u'D')
-        ax1.plot(x, [2] * 10, marker=u'x')
-        ax1.plot(x, [3] * 10, marker=u'^')
-        ax1.plot(x, [4] * 10, marker=u'H')
-        ax1.plot(x, [5] * 10, marker=u'v')
-
-    if 'h' in objects:
-        # also use different hatch patterns
-        ax2 = fig.add_subplot(1, 6, 2)
-        bars = ax2.bar(range(1, 5), range(1, 5)) + \
-               ax2.bar(range(1, 5), [6] * 4, bottom=range(1, 5))
-        ax2.set_xticks([1.5, 2.5, 3.5, 4.5])
-
-        patterns = ('-', '+', 'x', '\\', '*', 'o', 'O', '.')
-        for bar, pattern in zip(bars, patterns):
-            bar.set_hatch(pattern)
-
-    if 'i' in objects:
-        # also use different images
-        A = [[1, 2, 3], [2, 3, 1], [3, 1, 2]]
-        fig.add_subplot(1, 6, 3).imshow(A, interpolation='nearest')
-        A = [[1, 3, 2], [1, 2, 3], [3, 1, 2]]
-        fig.add_subplot(1, 6, 4).imshow(A, interpolation='bilinear')
-        A = [[2, 3, 1], [1, 2, 3], [2, 1, 3]]
-        fig.add_subplot(1, 6, 5).imshow(A, interpolation='bicubic')
-
-    x=range(5)
-    fig.add_subplot(1, 6, 6).plot(x,x)
-
-    fig.savefig(filename, format="pdf")
-
-    # Restores SOURCE_DATE_EPOCH
-    if sde == None:
-        os.environ.pop('SOURCE_DATE_EPOCH',None)
-    else:
-        os.environ['SOURCE_DATE_EPOCH'] = sde
-
-
-def _test_determinism(objects=''):
-    import sys
-    from subprocess import check_call
-    from nose.tools import assert_equal
-    filename = 'determinism_O%s.pdf' % objects
-    plots = []
-    for i in range(3):
-        check_call([sys.executable, '-R', '-c',
-                    'import matplotlib; '
-                    'matplotlib.use("pdf"); '
-                    'from matplotlib.tests.test_backend_pdf '
-                    'import _test_determinism_save;'
-                    '_test_determinism_save(%r,%r)' % (filename,objects)])
-        with open(filename, 'rb') as fd:
-            plots.append(fd.read())
-        os.unlink(filename)
-    for p in plots[1:]:
-        assert_equal(p,plots[0])
-
+    """Test SOURCE_DATE_EPOCH support for PDF output"""
+    _test_source_date_epoch("pdf", b"/CreationDate (D:20000101000000Z)")
 
 @cleanup
 def test_determinism_plain():
     """Test for reproducible PDF output: simple figure"""
-    _test_determinism()
+    _test_determinism('', format="pdf")
 
 
 @cleanup
 def test_determinism_images():
     """Test for reproducible PDF output: figure with different images"""
-    _test_determinism('i')
+    _test_determinism('i', format="pdf")
 
 
 @cleanup
 def test_determinism_hatches():
     """Test for reproducible PDF output: figure with different hatches"""
-    _test_determinism('h')
+    _test_determinism('h', format="pdf")
 
 
 @cleanup
 def test_determinism_markers():
     """Test for reproducible PDF output: figure with different markers"""
-    _test_determinism('m')
+    _test_determinism('m', format="pdf")
 
 
 @cleanup
 def test_determinism_all():
     """Test for reproducible PDF output"""
-    _test_determinism('mhi')
+    _test_determinism(format="pdf")
 
 
 @image_comparison(baseline_images=['hatching_legend'],
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index f017164ff7bb..f93f0bcce7e3 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -11,6 +11,7 @@
 import matplotlib
 import matplotlib.pyplot as plt
 from matplotlib import patheffects
+from matplotlib.testing.determinism import _test_source_date_epoch, _test_determinism
 from matplotlib.testing.decorators import cleanup, knownfailureif
 
 
@@ -173,6 +174,17 @@ def test_tilde_in_tempfilename():
                 # do not break if this is not removeable...
                 print(e)
 
+@cleanup
+def test_source_date_epoch():
+    """Test SOURCE_DATE_EPOCH support for PS output"""
+    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
+
+@cleanup
+def test_determinism_all():
+    """Test for reproducible PS output"""
+    _test_determinism(format="ps")
+
+
 
 if __name__ == '__main__':
     import nose

From 37c28b4088992e9c2f8841cb64e921331386ce90 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Mon, 27 Jun 2016 20:59:42 +0200
Subject: [PATCH 06/30] Reproducible PS/tex output.

---
 lib/matplotlib/backends/backend_ps.py   |  9 ++++++++-
 lib/matplotlib/tests/test_backend_ps.py | 16 ++++++++++++++++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index 76b43fcb47a4..1659cf41a70e 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -1277,7 +1277,14 @@ def write(self, *kl, **kwargs):
             if title: print("%%Title: "+title, file=fh)
             print(("%%Creator: matplotlib version "
                          +__version__+", http://matplotlib.org/"), file=fh)
-            print("%%CreationDate: "+time.ctime(time.time()), file=fh)
+            # get source date from SOURCE_DATE_EPOCH, if set
+            # See https://reproducible-builds.org/specs/source-date-epoch/
+            source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
+            if source_date_epoch:
+                source_date = time.asctime(time.gmtime(int(source_date_epoch)))
+            else:
+                source_date = time.ctime()
+            print("%%CreationDate: "+source_date, file=fh)
             print("%%%%BoundingBox: %d %d %d %d" % bbox, file=fh)
             print("%%EndComments", file=fh)
 
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index f93f0bcce7e3..ea763a68d067 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -179,11 +179,27 @@ def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PS output"""
     _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
 
+@cleanup
+@needs_tex
+@needs_ghostscript
+def test_source_date_epoch_tex():
+    """Test SOURCE_DATE_EPOCH support for PS/tex output"""
+    matplotlib.rcParams['text.usetex'] = True
+    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
+
 @cleanup
 def test_determinism_all():
     """Test for reproducible PS output"""
     _test_determinism(format="ps")
 
+@cleanup
+@needs_tex
+@needs_ghostscript
+def test_determinism_all_tex():
+    """Test for reproducible PS/tex output"""
+    matplotlib.rcParams['text.usetex'] = True
+    _test_determinism(format="ps")
+
 
 
 if __name__ == '__main__':

From 2e1c773a818845dbd8646c4c5917665d738cd969 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Mon, 27 Jun 2016 21:30:55 +0200
Subject: [PATCH 07/30] Removes test_source_date_epoch_tex test, since this is
 ghostscript dependent.

---
 lib/matplotlib/tests/test_backend_ps.py | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index ea763a68d067..408f12ee301f 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -179,13 +179,9 @@ def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PS output"""
     _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
 
-@cleanup
-@needs_tex
-@needs_ghostscript
-def test_source_date_epoch_tex():
-    """Test SOURCE_DATE_EPOCH support for PS/tex output"""
-    matplotlib.rcParams['text.usetex'] = True
-    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
+# SOURCE_DATE_EPOCH support is not tested with text.usetex, because the produced
+# timestamp comes from ghostscript: %%CreationDate: D:20000101000000Z00\'00\',
+# and this could change with another ghostscript version.
 
 @cleanup
 def test_determinism_all():

From 541f97e7f4dff414f39214830c3544c34e940b0a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Mon, 27 Jun 2016 21:34:54 +0200
Subject: [PATCH 08/30] PEP8

---
 lib/matplotlib/testing/determinism.py    |  1 +
 lib/matplotlib/tests/test_backend_pdf.py |  8 +++++---
 lib/matplotlib/tests/test_backend_ps.py  | 15 +++++++++------
 3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index f32286d7803c..bd0f623f154d 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -92,6 +92,7 @@ def _test_determinism(objects='mhi', format="pdf"):
     for p in plots[1:]:
         assert_equal(p, plots[0])
 
+
 def _test_source_date_epoch(format, string):
     """
     Test SOURCE_DATE_EPOCH support. Output a document with the envionment
diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
index 4b038a3e685f..43260e0a92f9 100644
--- a/lib/matplotlib/tests/test_backend_pdf.py
+++ b/lib/matplotlib/tests/test_backend_pdf.py
@@ -12,7 +12,8 @@
 from matplotlib import cm, rcParams
 from matplotlib.backends.backend_pdf import PdfPages
 from matplotlib import pyplot as plt
-from matplotlib.testing.determinism import _test_source_date_epoch, _test_determinism
+from matplotlib.testing.determinism import (_test_source_date_epoch,
+                                            _test_determinism)
 from matplotlib.testing.decorators import (image_comparison, knownfailureif,
                                            cleanup)
 
@@ -91,8 +92,8 @@ def test_multipage_keep_empty():
 
 @cleanup
 def test_composite_image():
-    #Test that figures can be saved with and without combining multiple images
-    #(on a single set of axes) into a single composite image.
+    # Test that figures can be saved with and without combining multiple images
+    # (on a single set of axes) into a single composite image.
     X, Y = np.meshgrid(np.arange(-5, 5, 1), np.arange(-5, 5, 1))
     Z = np.sin(Y ** 2)
     fig = plt.figure()
@@ -115,6 +116,7 @@ def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PDF output"""
     _test_source_date_epoch("pdf", b"/CreationDate (D:20000101000000Z)")
 
+
 @cleanup
 def test_determinism_plain():
     """Test for reproducible PDF output: simple figure"""
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index 408f12ee301f..5fa190ae4478 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -11,7 +11,8 @@
 import matplotlib
 import matplotlib.pyplot as plt
 from matplotlib import patheffects
-from matplotlib.testing.determinism import _test_source_date_epoch, _test_determinism
+from matplotlib.testing.determinism import (_test_source_date_epoch,
+                                            _test_determinism)
 from matplotlib.testing.decorators import cleanup, knownfailureif
 
 
@@ -161,7 +162,7 @@ def test_tilde_in_tempfilename():
         plt.rc('text', usetex=True)
         plt.plot([1, 2, 3, 4])
         plt.xlabel(r'\textbf{time} (s)')
-        #matplotlib.verbose.set_level("debug")
+        # matplotlib.verbose.set_level("debug")
         output_eps = os.path.join(base_tempdir, 'tex_demo.eps')
         # use the PS backend to write the file...
         plt.savefig(output_eps, format="ps")
@@ -174,20 +175,23 @@ def test_tilde_in_tempfilename():
                 # do not break if this is not removeable...
                 print(e)
 
+
 @cleanup
 def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PS output"""
+    # SOURCE_DATE_EPOCH support is not tested with text.usetex,
+    # because the produced timestamp comes from ghostscript:
+    # %%CreationDate: D:20000101000000Z00\'00\', and this could change
+    # with another ghostscript version.
     _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
 
-# SOURCE_DATE_EPOCH support is not tested with text.usetex, because the produced
-# timestamp comes from ghostscript: %%CreationDate: D:20000101000000Z00\'00\',
-# and this could change with another ghostscript version.
 
 @cleanup
 def test_determinism_all():
     """Test for reproducible PS output"""
     _test_determinism(format="ps")
 
+
 @cleanup
 @needs_tex
 @needs_ghostscript
@@ -197,7 +201,6 @@ def test_determinism_all_tex():
     _test_determinism(format="ps")
 
 
-
 if __name__ == '__main__':
     import nose
     nose.runmodule(argv=['-s', '--with-doctest'], exit=False)

From 2a6ebc8092234d8a25dd3bd853221260b4a50e8b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Thu, 7 Jul 2016 16:26:02 +0200
Subject: [PATCH 09/30] Add what's new section

---
 doc/users/whats_new/reproducible_ps_pdf.rst | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 doc/users/whats_new/reproducible_ps_pdf.rst

diff --git a/doc/users/whats_new/reproducible_ps_pdf.rst b/doc/users/whats_new/reproducible_ps_pdf.rst
new file mode 100644
index 000000000000..fe937b2863a8
--- /dev/null
+++ b/doc/users/whats_new/reproducible_ps_pdf.rst
@@ -0,0 +1,6 @@
+Reproducible PS and PDF output
+------------------------------
+
+The ``SOURCE_DATE_EPOCH`` environment variable can now be used to set
+the timestamps value in the PS and PDF outputs, which are then
+reproducible.

From 6ee896710b395552349cc698683949b6137e6b1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Fri, 8 Jul 2016 11:20:27 +0200
Subject: [PATCH 10/30] Add some insight when test_source_date_epoch fails.

---
 lib/matplotlib/testing/determinism.py | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index bd0f623f154d..4ec8f8b7ab0c 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -4,6 +4,7 @@
 
 import io
 import os
+import re
 
 from matplotlib import pyplot as plt
 
@@ -93,7 +94,7 @@ def _test_determinism(objects='mhi', format="pdf"):
         assert_equal(p, plots[0])
 
 
-def _test_source_date_epoch(format, string):
+def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
     """
     Test SOURCE_DATE_EPOCH support. Output a document with the envionment
     variable SOURCE_DATE_EPOCH set to 2000-01-01 00:00 UTC and check that the
@@ -106,6 +107,9 @@ def _test_source_date_epoch(format, string):
         format string, such as "pdf".
     string : str
         timestamp string for 2000-01-01 00:00 UTC.
+    keyword : str
+        a string to look at when searching for the timestamp in the document
+        (used in case the test fails).
     """
     try:
         # save current value of SOURCE_DATE_EPOCH
@@ -115,10 +119,16 @@ def _test_source_date_epoch(format, string):
         x = [1, 2, 3, 4, 5]
         ax.plot(x, x)
         os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+        find_keyword = re.compile(b".*" + keyword + b".*")
         with io.BytesIO() as output:
             fig.savefig(output, format=format)
             output.seek(0)
             buff = output.read()
+            key = find_keyword.search(buff)
+            if key:
+                print(key.group())
+            else:
+                print("Timestamp keyword (%s) not found!" % keyword)
             assert string in buff
         os.environ.pop('SOURCE_DATE_EPOCH', None)
         with io.BytesIO() as output:

From a3185e62cb92ffd65d020b78f183fe848c9f1da7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Fri, 8 Jul 2016 12:16:00 +0200
Subject: [PATCH 11/30] Allow parallel execution of
 test_backend_ps:test_determinism_all_tex and test_determinism_all

---
 lib/matplotlib/testing/determinism.py   | 7 +++++--
 lib/matplotlib/tests/test_backend_ps.py | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 4ec8f8b7ab0c..840c20fa4bf3 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -60,7 +60,7 @@ def _test_determinism_save(filename, objects='mhi', format="pdf"):
         os.environ['SOURCE_DATE_EPOCH'] = sde
 
 
-def _test_determinism(objects='mhi', format="pdf"):
+def _test_determinism(objects='mhi', format="pdf", uid=""):
     """
     Output three times the same graphs and checks that the outputs are exactly
     the same.
@@ -73,11 +73,14 @@ def _test_determinism(objects='mhi', format="pdf"):
         default value is "mhi", so that the test includes all these objects.
     format : str
         format string. The default value is "pdf".
+    uid : str
+        some string to add to the filename used to store the output. Use it to
+        allow parallel execution of two tests with the same objects parameter.
     """
     import sys
     from subprocess import check_call
     from nose.tools import assert_equal
-    filename = 'determinism_O%s.%s' % (objects, format)
+    filename = 'determinism_O%s%s.%s' % (objects, uid, format)
     plots = []
     for i in range(3):
         check_call([sys.executable, '-R', '-c',
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index 5fa190ae4478..3ebe3d0f711a 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -198,7 +198,7 @@ def test_determinism_all():
 def test_determinism_all_tex():
     """Test for reproducible PS/tex output"""
     matplotlib.rcParams['text.usetex'] = True
-    _test_determinism(format="ps")
+    _test_determinism(format="ps",uid="_tex")
 
 
 if __name__ == '__main__':

From 8f095f613b51aa5ec563bfe28e8e97cf9187be0e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Fri, 8 Jul 2016 12:43:05 +0200
Subject: [PATCH 12/30] Use subprocess for _test_source_date_epoch, to allow
 parallel calls (environment is shared between threads).

---
 lib/matplotlib/testing/determinism.py | 49 +++++++++++----------------
 1 file changed, 19 insertions(+), 30 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 840c20fa4bf3..30e40d22fc53 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -114,34 +114,23 @@ def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
         a string to look at when searching for the timestamp in the document
         (used in case the test fails).
     """
-    try:
-        # save current value of SOURCE_DATE_EPOCH
-        sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
-        fig = plt.figure()
-        ax = fig.add_subplot(1, 1, 1)
-        x = [1, 2, 3, 4, 5]
-        ax.plot(x, x)
-        os.environ['SOURCE_DATE_EPOCH'] = "946684800"
-        find_keyword = re.compile(b".*" + keyword + b".*")
-        with io.BytesIO() as output:
-            fig.savefig(output, format=format)
-            output.seek(0)
-            buff = output.read()
-            key = find_keyword.search(buff)
-            if key:
-                print(key.group())
-            else:
-                print("Timestamp keyword (%s) not found!" % keyword)
-            assert string in buff
-        os.environ.pop('SOURCE_DATE_EPOCH', None)
-        with io.BytesIO() as output:
-            fig.savefig(output, format=format)
-            output.seek(0)
-            buff = output.read()
-            assert string not in buff
-    finally:
-        # Restores SOURCE_DATE_EPOCH
-        if sde is None:
-            os.environ.pop('SOURCE_DATE_EPOCH', None)
+    import sys
+    from subprocess import check_call
+    filename = 'test_SDE_on.%s' % format
+    check_call([sys.executable, '-R', '-c',
+                'import matplotlib; '
+                'matplotlib.use(%r); '
+                'from matplotlib.testing.determinism '
+                'import _test_determinism_save;'
+                '_test_determinism_save(%r,%r,%r)'
+                % (format, filename, "", format)])
+    find_keyword = re.compile(b".*" + keyword + b".*")
+    with open(filename, 'rb') as fd:
+        buff = fd.read()
+        key = find_keyword.search(buff)
+        if key:
+            print(key.group())
         else:
-            os.environ['SOURCE_DATE_EPOCH'] = sde
+            print("Timestamp keyword (%s) not found!" % keyword)
+        assert string in buff
+    os.unlink(filename)

From c007f4998a3e4ab411c8dd58ab186ced4c179ca7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Mon, 11 Jul 2016 09:51:52 +0200
Subject: [PATCH 13/30] Change SOURCE_DATE_EPOCH test date, to use two-digits
 numbers for month, day of month and times. This way we don't mind if
 timestamps are written with leading 0 or space.

---
 lib/matplotlib/testing/determinism.py    | 6 +++---
 lib/matplotlib/tests/test_backend_pdf.py | 2 +-
 lib/matplotlib/tests/test_backend_ps.py  | 4 ++--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 30e40d22fc53..82fc5d7a640c 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -14,7 +14,7 @@ def _test_determinism_save(filename, objects='mhi', format="pdf"):
     # to a constant value, so that time difference is not
     # taken into account
     sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
-    os.environ['SOURCE_DATE_EPOCH'] = "946684800"
+    os.environ['SOURCE_DATE_EPOCH'] = "976875010"
 
     fig = plt.figure()
 
@@ -100,7 +100,7 @@ def _test_determinism(objects='mhi', format="pdf", uid=""):
 def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
     """
     Test SOURCE_DATE_EPOCH support. Output a document with the envionment
-    variable SOURCE_DATE_EPOCH set to 2000-01-01 00:00 UTC and check that the
+    variable SOURCE_DATE_EPOCH set to 2000-12-15 10:10:10 UTC and check that the
     document contains the timestamp that corresponds to this date (given as an
     argument).
 
@@ -109,7 +109,7 @@ def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
     format : str
         format string, such as "pdf".
     string : str
-        timestamp string for 2000-01-01 00:00 UTC.
+        timestamp string for 2000-12-15 10:10:10 UTC.
     keyword : str
         a string to look at when searching for the timestamp in the document
         (used in case the test fails).
diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
index 43260e0a92f9..7586a3b205e3 100644
--- a/lib/matplotlib/tests/test_backend_pdf.py
+++ b/lib/matplotlib/tests/test_backend_pdf.py
@@ -114,7 +114,7 @@ def test_composite_image():
 @cleanup
 def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PDF output"""
-    _test_source_date_epoch("pdf", b"/CreationDate (D:20000101000000Z)")
+    _test_source_date_epoch("pdf", b"/CreationDate (D:20001215101010Z)")
 
 
 @cleanup
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index 3ebe3d0f711a..7fcdf0d3dbfa 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -181,9 +181,9 @@ def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PS output"""
     # SOURCE_DATE_EPOCH support is not tested with text.usetex,
     # because the produced timestamp comes from ghostscript:
-    # %%CreationDate: D:20000101000000Z00\'00\', and this could change
+    # %%CreationDate: D:20001215101010Z00\'00\', and this could change
     # with another ghostscript version.
-    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
+    _test_source_date_epoch("ps", b"%%CreationDate: Fri Dec 15 10:10:10 2000")
 
 
 @cleanup

From ecbdd551c74f20ecac9b98ccc3f20915b95705ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Mon, 11 Jul 2016 09:59:29 +0200
Subject: [PATCH 14/30] PEP8

---
 lib/matplotlib/testing/determinism.py   | 6 +++---
 lib/matplotlib/tests/test_backend_ps.py | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 82fc5d7a640c..94cc0f14dd6b 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -100,9 +100,9 @@ def _test_determinism(objects='mhi', format="pdf", uid=""):
 def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
     """
     Test SOURCE_DATE_EPOCH support. Output a document with the envionment
-    variable SOURCE_DATE_EPOCH set to 2000-12-15 10:10:10 UTC and check that the
-    document contains the timestamp that corresponds to this date (given as an
-    argument).
+    variable SOURCE_DATE_EPOCH set to 2000-12-15 10:10:10 UTC and check that
+    the document contains the timestamp that corresponds to this date (given as
+    an argument).
 
     Parameters
     ----------
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index 7fcdf0d3dbfa..bac1abaed288 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -198,7 +198,7 @@ def test_determinism_all():
 def test_determinism_all_tex():
     """Test for reproducible PS/tex output"""
     matplotlib.rcParams['text.usetex'] = True
-    _test_determinism(format="ps",uid="_tex")
+    _test_determinism(format="ps", uid="_tex")
 
 
 if __name__ == '__main__':

From 65ec88e265da535edd819e3c2923feb546b3c2a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 12 Jul 2016 09:16:29 +0200
Subject: [PATCH 15/30] Warnings about possible unreproducibility issues

---
 doc/users/whats_new/reproducible_ps_pdf.rst | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/doc/users/whats_new/reproducible_ps_pdf.rst b/doc/users/whats_new/reproducible_ps_pdf.rst
index fe937b2863a8..94c39f766ac8 100644
--- a/doc/users/whats_new/reproducible_ps_pdf.rst
+++ b/doc/users/whats_new/reproducible_ps_pdf.rst
@@ -2,5 +2,12 @@ Reproducible PS and PDF output
 ------------------------------
 
 The ``SOURCE_DATE_EPOCH`` environment variable can now be used to set
-the timestamps value in the PS and PDF outputs, which are then
-reproducible.
+the timestamps value in the PS and PDF outputs. See
+https://reproducible-builds.org/specs/source-date-epoch/
+
+Matplotlib does its best to make PS and PDF outputs reproducible, but
+be aware that some unreproducibility issues can arise if you use
+different versions of Matplotlib and the tools it relies on. Although
+standard plots has been checked to be reproducible, external tools can
+also be a source of nondeterminism (``mathtext``, ``ps.usedistiller``,
+``ps.fonttype``, ``pdf.fonttype``...).

From 5b405cc935f70590c2c7e0f667454527940ca123 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 12 Jul 2016 23:30:19 +0200
Subject: [PATCH 16/30] Doc rephrasing, thanks to jkseppan.

---
 doc/users/whats_new/reproducible_ps_pdf.rst | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/doc/users/whats_new/reproducible_ps_pdf.rst b/doc/users/whats_new/reproducible_ps_pdf.rst
index 94c39f766ac8..97585a674b50 100644
--- a/doc/users/whats_new/reproducible_ps_pdf.rst
+++ b/doc/users/whats_new/reproducible_ps_pdf.rst
@@ -5,9 +5,10 @@ The ``SOURCE_DATE_EPOCH`` environment variable can now be used to set
 the timestamps value in the PS and PDF outputs. See
 https://reproducible-builds.org/specs/source-date-epoch/
 
-Matplotlib does its best to make PS and PDF outputs reproducible, but
-be aware that some unreproducibility issues can arise if you use
-different versions of Matplotlib and the tools it relies on. Although
-standard plots has been checked to be reproducible, external tools can
-also be a source of nondeterminism (``mathtext``, ``ps.usedistiller``,
-``ps.fonttype``, ``pdf.fonttype``...).
+The reproducibility of the output from the PS and PDF backends has so
+far been tested using various plot elements but only default values of
+options such as ``{ps,pdf}.fonttype`` that can affect the output at a
+low level, and not with the mathtext or usetex features. When
+matplotlib calls external tools (such as PS distillers or LaTeX) their
+versions need to be kept constant for reproducibility, and they may
+add sources of nondeterminism outside the control of matplotlib.

From d10a21ece008d91a46d93a92e69542bed39bb3cb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 12 Jul 2016 23:53:07 +0200
Subject: [PATCH 17/30] Use explicit date formatting for PS backend timestamp,
 instead of asctime

---
 lib/matplotlib/backends/backend_ps.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index 1659cf41a70e..496e1f53f58c 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -8,7 +8,7 @@
 import six
 from six.moves import StringIO
 
-import glob, math, os, shutil, sys, time
+import glob, math, os, shutil, sys, time, datetime
 def _fn_name(): return sys._getframe(1).f_code.co_name
 import io
 
@@ -1091,7 +1091,8 @@ def print_figure_impl():
             # See https://reproducible-builds.org/specs/source-date-epoch/
             source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
             if source_date_epoch:
-                source_date = time.asctime(time.gmtime(int(source_date_epoch)))
+                source_date = datetime.datetime.utcfromtimestamp(
+                    int(source_date_epoch) ).strftime("%a %b %e %T %Y")
             else:
                 source_date = time.ctime()
             print("%%CreationDate: "+source_date, file=fh)
@@ -1281,7 +1282,8 @@ def write(self, *kl, **kwargs):
             # See https://reproducible-builds.org/specs/source-date-epoch/
             source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
             if source_date_epoch:
-                source_date = time.asctime(time.gmtime(int(source_date_epoch)))
+                source_date = datetime.datetime.utcfromtimestamp(
+                    int(source_date_epoch) ).strftime("%a %b %e %T %Y")
             else:
                 source_date = time.ctime()
             print("%%CreationDate: "+source_date, file=fh)

From da55bb66592964f5a15ffc370d035c2a4691ea88 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 12 Jul 2016 23:56:40 +0200
Subject: [PATCH 18/30] Revert to 2000-01-01 for the SOURCE_DATE_EPOCH test
 date.

This reverts commit c007f4998a3e4ab411c8dd58ab186ced4c179ca7.
---
 lib/matplotlib/testing/determinism.py    | 10 +++++-----
 lib/matplotlib/tests/test_backend_pdf.py |  2 +-
 lib/matplotlib/tests/test_backend_ps.py  |  4 ++--
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 94cc0f14dd6b..30e40d22fc53 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -14,7 +14,7 @@ def _test_determinism_save(filename, objects='mhi', format="pdf"):
     # to a constant value, so that time difference is not
     # taken into account
     sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
-    os.environ['SOURCE_DATE_EPOCH'] = "976875010"
+    os.environ['SOURCE_DATE_EPOCH'] = "946684800"
 
     fig = plt.figure()
 
@@ -100,16 +100,16 @@ def _test_determinism(objects='mhi', format="pdf", uid=""):
 def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
     """
     Test SOURCE_DATE_EPOCH support. Output a document with the envionment
-    variable SOURCE_DATE_EPOCH set to 2000-12-15 10:10:10 UTC and check that
-    the document contains the timestamp that corresponds to this date (given as
-    an argument).
+    variable SOURCE_DATE_EPOCH set to 2000-01-01 00:00 UTC and check that the
+    document contains the timestamp that corresponds to this date (given as an
+    argument).
 
     Parameters
     ----------
     format : str
         format string, such as "pdf".
     string : str
-        timestamp string for 2000-12-15 10:10:10 UTC.
+        timestamp string for 2000-01-01 00:00 UTC.
     keyword : str
         a string to look at when searching for the timestamp in the document
         (used in case the test fails).
diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
index 7586a3b205e3..43260e0a92f9 100644
--- a/lib/matplotlib/tests/test_backend_pdf.py
+++ b/lib/matplotlib/tests/test_backend_pdf.py
@@ -114,7 +114,7 @@ def test_composite_image():
 @cleanup
 def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PDF output"""
-    _test_source_date_epoch("pdf", b"/CreationDate (D:20001215101010Z)")
+    _test_source_date_epoch("pdf", b"/CreationDate (D:20000101000000Z)")
 
 
 @cleanup
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index bac1abaed288..30977c03db44 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -181,9 +181,9 @@ def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PS output"""
     # SOURCE_DATE_EPOCH support is not tested with text.usetex,
     # because the produced timestamp comes from ghostscript:
-    # %%CreationDate: D:20001215101010Z00\'00\', and this could change
+    # %%CreationDate: D:20000101000000Z00\'00\', and this could change
     # with another ghostscript version.
-    _test_source_date_epoch("ps", b"%%CreationDate: Fri Dec 15 10:10:10 2000")
+    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
 
 
 @cleanup

From c56dae7c52af50ceaca33ba1471758c16ff86077 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Wed, 13 Jul 2016 18:04:07 +0200
Subject: [PATCH 19/30] Use standard date format for PS timestamp

---
 lib/matplotlib/backends/backend_ps.py   | 2 +-
 lib/matplotlib/tests/test_backend_ps.py | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index 496e1f53f58c..fa4c7b285418 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -1092,7 +1092,7 @@ def print_figure_impl():
             source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
             if source_date_epoch:
                 source_date = datetime.datetime.utcfromtimestamp(
-                    int(source_date_epoch) ).strftime("%a %b %e %T %Y")
+                    int(source_date_epoch) ).strftime("%a %b %d %H:%M:%S %Y")
             else:
                 source_date = time.ctime()
             print("%%CreationDate: "+source_date, file=fh)
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index 30977c03db44..ebc636cb4da2 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -183,7 +183,7 @@ def test_source_date_epoch():
     # because the produced timestamp comes from ghostscript:
     # %%CreationDate: D:20000101000000Z00\'00\', and this could change
     # with another ghostscript version.
-    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan  1 00:00:00 2000")
+    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan 01 00:00:00 2000")
 
 
 @cleanup

From 995173d6ef9a1dd0b1012c2729e177b89b9e9d3e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 4 Oct 2016 11:15:09 +0200
Subject: [PATCH 20/30] Rename functions in determinism.py to remove `test'
 keyword, since these are not main testing functions.

---
 lib/matplotlib/testing/determinism.py    | 14 +++++++-------
 lib/matplotlib/tests/test_backend_pdf.py | 16 ++++++++--------
 lib/matplotlib/tests/test_backend_ps.py  | 11 ++++++-----
 3 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 30e40d22fc53..d5508a76d974 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -9,7 +9,7 @@
 from matplotlib import pyplot as plt
 
 
-def _test_determinism_save(filename, objects='mhi', format="pdf"):
+def _determinism_save(filename, objects='mhi', format="pdf"):
     # save current value of SOURCE_DATE_EPOCH and set it
     # to a constant value, so that time difference is not
     # taken into account
@@ -60,7 +60,7 @@ def _test_determinism_save(filename, objects='mhi', format="pdf"):
         os.environ['SOURCE_DATE_EPOCH'] = sde
 
 
-def _test_determinism(objects='mhi', format="pdf", uid=""):
+def _determinism_check(objects='mhi', format="pdf", uid=""):
     """
     Output three times the same graphs and checks that the outputs are exactly
     the same.
@@ -87,8 +87,8 @@ def _test_determinism(objects='mhi', format="pdf", uid=""):
                     'import matplotlib; '
                     'matplotlib.use(%r); '
                     'from matplotlib.testing.determinism '
-                    'import _test_determinism_save;'
-                    '_test_determinism_save(%r,%r,%r)'
+                    'import _determinism_save;'
+                    '_determinism_save(%r,%r,%r)'
                     % (format, filename, objects, format)])
         with open(filename, 'rb') as fd:
             plots.append(fd.read())
@@ -97,7 +97,7 @@ def _test_determinism(objects='mhi', format="pdf", uid=""):
         assert_equal(p, plots[0])
 
 
-def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
+def _determinism_source_date_epoch(format, string, keyword=b"CreationDate"):
     """
     Test SOURCE_DATE_EPOCH support. Output a document with the envionment
     variable SOURCE_DATE_EPOCH set to 2000-01-01 00:00 UTC and check that the
@@ -121,8 +121,8 @@ def _test_source_date_epoch(format, string, keyword=b"CreationDate"):
                 'import matplotlib; '
                 'matplotlib.use(%r); '
                 'from matplotlib.testing.determinism '
-                'import _test_determinism_save;'
-                '_test_determinism_save(%r,%r,%r)'
+                'import _determinism_save;'
+                '_determinism_save(%r,%r,%r)'
                 % (format, filename, "", format)])
     find_keyword = re.compile(b".*" + keyword + b".*")
     with open(filename, 'rb') as fd:
diff --git a/lib/matplotlib/tests/test_backend_pdf.py b/lib/matplotlib/tests/test_backend_pdf.py
index 43260e0a92f9..dd4dc95aca1a 100644
--- a/lib/matplotlib/tests/test_backend_pdf.py
+++ b/lib/matplotlib/tests/test_backend_pdf.py
@@ -12,8 +12,8 @@
 from matplotlib import cm, rcParams
 from matplotlib.backends.backend_pdf import PdfPages
 from matplotlib import pyplot as plt
-from matplotlib.testing.determinism import (_test_source_date_epoch,
-                                            _test_determinism)
+from matplotlib.testing.determinism import (_determinism_source_date_epoch,
+                                            _determinism_check)
 from matplotlib.testing.decorators import (image_comparison, knownfailureif,
                                            cleanup)
 
@@ -114,37 +114,37 @@ def test_composite_image():
 @cleanup
 def test_source_date_epoch():
     """Test SOURCE_DATE_EPOCH support for PDF output"""
-    _test_source_date_epoch("pdf", b"/CreationDate (D:20000101000000Z)")
+    _determinism_source_date_epoch("pdf", b"/CreationDate (D:20000101000000Z)")
 
 
 @cleanup
 def test_determinism_plain():
     """Test for reproducible PDF output: simple figure"""
-    _test_determinism('', format="pdf")
+    _determinism_check('', format="pdf")
 
 
 @cleanup
 def test_determinism_images():
     """Test for reproducible PDF output: figure with different images"""
-    _test_determinism('i', format="pdf")
+    _determinism_check('i', format="pdf")
 
 
 @cleanup
 def test_determinism_hatches():
     """Test for reproducible PDF output: figure with different hatches"""
-    _test_determinism('h', format="pdf")
+    _determinism_check('h', format="pdf")
 
 
 @cleanup
 def test_determinism_markers():
     """Test for reproducible PDF output: figure with different markers"""
-    _test_determinism('m', format="pdf")
+    _determinism_check('m', format="pdf")
 
 
 @cleanup
 def test_determinism_all():
     """Test for reproducible PDF output"""
-    _test_determinism(format="pdf")
+    _determinism_check(format="pdf")
 
 
 @image_comparison(baseline_images=['hatching_legend'],
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index ebc636cb4da2..4e61f324a326 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -11,8 +11,8 @@
 import matplotlib
 import matplotlib.pyplot as plt
 from matplotlib import patheffects
-from matplotlib.testing.determinism import (_test_source_date_epoch,
-                                            _test_determinism)
+from matplotlib.testing.determinism import (_determinism_source_date_epoch,
+                                            _determinism_check)
 from matplotlib.testing.decorators import cleanup, knownfailureif
 
 
@@ -183,13 +183,14 @@ def test_source_date_epoch():
     # because the produced timestamp comes from ghostscript:
     # %%CreationDate: D:20000101000000Z00\'00\', and this could change
     # with another ghostscript version.
-    _test_source_date_epoch("ps", b"%%CreationDate: Sat Jan 01 00:00:00 2000")
+    _determinism_source_date_epoch(
+        "ps", b"%%CreationDate: Sat Jan 01 00:00:00 2000")
 
 
 @cleanup
 def test_determinism_all():
     """Test for reproducible PS output"""
-    _test_determinism(format="ps")
+    _determinism_check(format="ps")
 
 
 @cleanup
@@ -198,7 +199,7 @@ def test_determinism_all():
 def test_determinism_all_tex():
     """Test for reproducible PS/tex output"""
     matplotlib.rcParams['text.usetex'] = True
-    _test_determinism(format="ps", uid="_tex")
+    _determinism_check(format="ps", uid="_tex")
 
 
 if __name__ == '__main__':

From eef6b12b40426187a886ea83df027fd7400b4151 Mon Sep 17 00:00:00 2001
From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
Date: Thu, 6 Oct 2016 20:33:56 -0400
Subject: [PATCH 21/30] TST: Use standard I/O for determinism tests.

---
 lib/matplotlib/testing/determinism.py | 58 ++++++++++++---------------
 1 file changed, 26 insertions(+), 32 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index d5508a76d974..24c706ccf1be 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -9,10 +9,11 @@
 from matplotlib import pyplot as plt
 
 
-def _determinism_save(filename, objects='mhi', format="pdf"):
+def _determinism_save(objects='mhi', format="pdf"):
     # save current value of SOURCE_DATE_EPOCH and set it
     # to a constant value, so that time difference is not
     # taken into account
+    import sys
     sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
     os.environ['SOURCE_DATE_EPOCH'] = "946684800"
 
@@ -51,7 +52,7 @@ def _determinism_save(filename, objects='mhi', format="pdf"):
     x = range(5)
     fig.add_subplot(1, 6, 6).plot(x, x)
 
-    fig.savefig(filename, format=format)
+    fig.savefig(sys.stdout.buffer, format=format)
 
     # Restores SOURCE_DATE_EPOCH
     if sde is None:
@@ -78,21 +79,18 @@ def _determinism_check(objects='mhi', format="pdf", uid=""):
         allow parallel execution of two tests with the same objects parameter.
     """
     import sys
-    from subprocess import check_call
+    from subprocess import check_output
     from nose.tools import assert_equal
-    filename = 'determinism_O%s%s.%s' % (objects, uid, format)
     plots = []
     for i in range(3):
-        check_call([sys.executable, '-R', '-c',
-                    'import matplotlib; '
-                    'matplotlib.use(%r); '
-                    'from matplotlib.testing.determinism '
-                    'import _determinism_save;'
-                    '_determinism_save(%r,%r,%r)'
-                    % (format, filename, objects, format)])
-        with open(filename, 'rb') as fd:
-            plots.append(fd.read())
-        os.unlink(filename)
+        result = check_output([sys.executable, '-R', '-c',
+                               'import matplotlib; '
+                               'matplotlib.use(%r); '
+                               'from matplotlib.testing.determinism '
+                               'import _determinism_save;'
+                               '_determinism_save(%r,%r)'
+                               % (format, objects, format)])
+        plots.append(result)
     for p in plots[1:]:
         assert_equal(p, plots[0])
 
@@ -115,22 +113,18 @@ def _determinism_source_date_epoch(format, string, keyword=b"CreationDate"):
         (used in case the test fails).
     """
     import sys
-    from subprocess import check_call
-    filename = 'test_SDE_on.%s' % format
-    check_call([sys.executable, '-R', '-c',
-                'import matplotlib; '
-                'matplotlib.use(%r); '
-                'from matplotlib.testing.determinism '
-                'import _determinism_save;'
-                '_determinism_save(%r,%r,%r)'
-                % (format, filename, "", format)])
+    from subprocess import check_output
+    buff = check_output([sys.executable, '-R', '-c',
+                         'import matplotlib; '
+                         'matplotlib.use(%r); '
+                         'from matplotlib.testing.determinism '
+                         'import _determinism_save;'
+                         '_determinism_save(%r,%r)'
+                         % (format, "", format)])
     find_keyword = re.compile(b".*" + keyword + b".*")
-    with open(filename, 'rb') as fd:
-        buff = fd.read()
-        key = find_keyword.search(buff)
-        if key:
-            print(key.group())
-        else:
-            print("Timestamp keyword (%s) not found!" % keyword)
-        assert string in buff
-    os.unlink(filename)
+    key = find_keyword.search(buff)
+    if key:
+        print(key.group())
+    else:
+        print("Timestamp keyword (%s) not found!" % keyword)
+    assert string in buff

From fb529da81aee18cd646c5500758d480a0611a67f Mon Sep 17 00:00:00 2001
From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
Date: Thu, 6 Oct 2016 20:39:59 -0400
Subject: [PATCH 22/30] TST: Remove multiple nested imports.

---
 lib/matplotlib/testing/determinism.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 24c706ccf1be..b4e5bb9f0835 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -5,6 +5,8 @@
 import io
 import os
 import re
+import sys
+from subprocess import check_output
 
 from matplotlib import pyplot as plt
 
@@ -13,7 +15,6 @@ def _determinism_save(objects='mhi', format="pdf"):
     # save current value of SOURCE_DATE_EPOCH and set it
     # to a constant value, so that time difference is not
     # taken into account
-    import sys
     sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
     os.environ['SOURCE_DATE_EPOCH'] = "946684800"
 
@@ -78,8 +79,6 @@ def _determinism_check(objects='mhi', format="pdf", uid=""):
         some string to add to the filename used to store the output. Use it to
         allow parallel execution of two tests with the same objects parameter.
     """
-    import sys
-    from subprocess import check_output
     from nose.tools import assert_equal
     plots = []
     for i in range(3):
@@ -112,8 +111,6 @@ def _determinism_source_date_epoch(format, string, keyword=b"CreationDate"):
         a string to look at when searching for the timestamp in the document
         (used in case the test fails).
     """
-    import sys
-    from subprocess import check_output
     buff = check_output([sys.executable, '-R', '-c',
                          'import matplotlib; '
                          'matplotlib.use(%r); '

From ebff832c6087cb2f646e94e6f3eb23afdcfc8dd0 Mon Sep 17 00:00:00 2001
From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
Date: Sat, 8 Oct 2016 00:26:34 -0400
Subject: [PATCH 23/30] TST: Fix compatibility with Python 2.

---
 lib/matplotlib/testing/determinism.py | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index b4e5bb9f0835..2a378ed6a094 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -2,6 +2,8 @@
 Provides utilities to test output reproducibility.
 """
 
+import six
+
 import io
 import os
 import re
@@ -53,7 +55,13 @@ def _determinism_save(objects='mhi', format="pdf"):
     x = range(5)
     fig.add_subplot(1, 6, 6).plot(x, x)
 
-    fig.savefig(sys.stdout.buffer, format=format)
+    if six.PY2 and format == 'ps':
+        stdout = io.StringIO()
+    else:
+        stdout = getattr(sys.stdout, 'buffer', sys.stdout)
+    fig.savefig(stdout, format=format)
+    if six.PY2 and format == 'ps':
+        sys.stdout.write(stdout.getvalue())
 
     # Restores SOURCE_DATE_EPOCH
     if sde is None:

From 1786555aa7c77ae56b2d1b52b737eef5457d5fdc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Sun, 9 Oct 2016 21:40:00 +0200
Subject: [PATCH 24/30] Adds __future__ imports to testing/determinism.py

---
 lib/matplotlib/testing/determinism.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 2a378ed6a094..396891771c94 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -2,6 +2,9 @@
 Provides utilities to test output reproducibility.
 """
 
+from __future__ import (absolute_import, division, print_function,
+                        unicode_literals)
+
 import six
 
 import io

From af4213ed07f1adaa77c9aaa8160904437ad8feeb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 11 Oct 2016 09:16:01 +0200
Subject: [PATCH 25/30] Pass usetex setting to _determinism_save

---
 lib/matplotlib/testing/determinism.py   | 11 +++++++----
 lib/matplotlib/tests/test_backend_ps.py |  3 +--
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 396891771c94..a74ff85e8d1a 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -13,16 +13,19 @@
 import sys
 from subprocess import check_output
 
+import matplotlib
 from matplotlib import pyplot as plt
 
 
-def _determinism_save(objects='mhi', format="pdf"):
+def _determinism_save(objects='mhi', format="pdf", usetex=False):
     # save current value of SOURCE_DATE_EPOCH and set it
     # to a constant value, so that time difference is not
     # taken into account
     sde = os.environ.pop('SOURCE_DATE_EPOCH', None)
     os.environ['SOURCE_DATE_EPOCH'] = "946684800"
 
+    matplotlib.rcParams['text.usetex'] = usetex
+
     fig = plt.figure()
 
     if 'm' in objects:
@@ -73,7 +76,7 @@ def _determinism_save(objects='mhi', format="pdf"):
         os.environ['SOURCE_DATE_EPOCH'] = sde
 
 
-def _determinism_check(objects='mhi', format="pdf", uid=""):
+def _determinism_check(objects='mhi', format="pdf", uid="", usetex=False):
     """
     Output three times the same graphs and checks that the outputs are exactly
     the same.
@@ -98,8 +101,8 @@ def _determinism_check(objects='mhi', format="pdf", uid=""):
                                'matplotlib.use(%r); '
                                'from matplotlib.testing.determinism '
                                'import _determinism_save;'
-                               '_determinism_save(%r,%r)'
-                               % (format, objects, format)])
+                               '_determinism_save(%r,%r,%r)'
+                               % (format, objects, format, usetex)])
         plots.append(result)
     for p in plots[1:]:
         assert_equal(p, plots[0])
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index 4e61f324a326..c2457ca3471d 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -198,8 +198,7 @@ def test_determinism_all():
 @needs_ghostscript
 def test_determinism_all_tex():
     """Test for reproducible PS/tex output"""
-    matplotlib.rcParams['text.usetex'] = True
-    _determinism_check(format="ps", uid="_tex")
+    _determinism_check(format="ps", uid="_tex", usetex=True)
 
 
 if __name__ == '__main__':

From bf7387e95fb26615e0a7bfeb80f7fdc0c9404318 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 11 Oct 2016 12:14:41 +0200
Subject: [PATCH 26/30] Skip test using ghostscript, since failing may be due
 to ghostscript timestamps

---
 lib/matplotlib/testing/determinism.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index a74ff85e8d1a..49b0eac936a9 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -16,6 +16,8 @@
 import matplotlib
 from matplotlib import pyplot as plt
 
+from nose.plugins.skip import SkipTest
+
 
 def _determinism_save(objects='mhi', format="pdf", usetex=False):
     # save current value of SOURCE_DATE_EPOCH and set it
@@ -105,7 +107,11 @@ def _determinism_check(objects='mhi', format="pdf", uid="", usetex=False):
                                % (format, objects, format, usetex)])
         plots.append(result)
     for p in plots[1:]:
-        assert_equal(p, plots[0])
+        if usetex:
+            if p != plots[0]:
+                raise SkipTest("failed, maybe due to ghostscript timestamps")
+        else:
+            assert_equal(p, plots[0])
 
 
 def _determinism_source_date_epoch(format, string, keyword=b"CreationDate"):

From 2cdc57741bb0643c70e0d0268c502cf6d53269b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Tue, 11 Oct 2016 16:40:17 +0200
Subject: [PATCH 27/30] Forgot to change one timestamp format in
 c56dae7c52af50ceaca33ba1471758c16ff86077

---
 lib/matplotlib/backends/backend_ps.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/matplotlib/backends/backend_ps.py b/lib/matplotlib/backends/backend_ps.py
index fa4c7b285418..6769e86659f5 100644
--- a/lib/matplotlib/backends/backend_ps.py
+++ b/lib/matplotlib/backends/backend_ps.py
@@ -1283,7 +1283,7 @@ def write(self, *kl, **kwargs):
             source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
             if source_date_epoch:
                 source_date = datetime.datetime.utcfromtimestamp(
-                    int(source_date_epoch) ).strftime("%a %b %e %T %Y")
+                    int(source_date_epoch) ).strftime("%a %b %d %H:%M:%S %Y")
             else:
                 source_date = time.ctime()
             print("%%CreationDate: "+source_date, file=fh)

From 76bec02fc2129f322d1e3cb052c671852d83aec3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Wed, 2 Nov 2016 15:20:30 +0100
Subject: [PATCH 28/30] Reuse UTC timezone from dates.py

---
 lib/matplotlib/backends/backend_pdf.py | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/lib/matplotlib/backends/backend_pdf.py b/lib/matplotlib/backends/backend_pdf.py
index a15e13c3a612..cedfe29e8b2a 100644
--- a/lib/matplotlib/backends/backend_pdf.py
+++ b/lib/matplotlib/backends/backend_pdf.py
@@ -46,6 +46,7 @@
 from matplotlib.mathtext import MathTextParser
 from matplotlib.transforms import Affine2D, BboxBase
 from matplotlib.path import Path
+from matplotlib.dates import UTC
 from matplotlib import _path
 from matplotlib import _png
 from matplotlib import ttconv
@@ -136,20 +137,6 @@ def _string_escape(match):
     assert False
 
 
-# tzinfo class for UTC
-class UTCtimezone(tzinfo):
-    """UTC timezone"""
-
-    def utcoffset(self, dt):
-        return timedelta(0)
-
-    def tzname(self, dt):
-        return "UTC"
-
-    def dst(self, dt):
-        return timedelta(0)
-
-
 def pdfRepr(obj):
     """Map Python objects to PDF syntax."""
 
@@ -492,7 +479,7 @@ def __init__(self, filename):
         source_date_epoch = os.getenv("SOURCE_DATE_EPOCH")
         if source_date_epoch:
             source_date = datetime.utcfromtimestamp(int(source_date_epoch))
-            source_date = source_date.replace(tzinfo=UTCtimezone())
+            source_date = source_date.replace(tzinfo=UTC)
         else:
             source_date = datetime.today()
 

From bbab0c578a278a612c9f6ffc44961d3a6201a6dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Thu, 3 Nov 2016 21:46:03 +0100
Subject: [PATCH 29/30] Removes now useless option uid for _determinism_check

---
 lib/matplotlib/testing/determinism.py   | 7 ++-----
 lib/matplotlib/tests/test_backend_ps.py | 2 +-
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/lib/matplotlib/testing/determinism.py b/lib/matplotlib/testing/determinism.py
index 49b0eac936a9..07b5e831451f 100644
--- a/lib/matplotlib/testing/determinism.py
+++ b/lib/matplotlib/testing/determinism.py
@@ -78,7 +78,7 @@ def _determinism_save(objects='mhi', format="pdf", usetex=False):
         os.environ['SOURCE_DATE_EPOCH'] = sde
 
 
-def _determinism_check(objects='mhi', format="pdf", uid="", usetex=False):
+def _determinism_check(objects='mhi', format="pdf", usetex=False):
     """
     Output three times the same graphs and checks that the outputs are exactly
     the same.
@@ -91,9 +91,6 @@ def _determinism_check(objects='mhi', format="pdf", uid="", usetex=False):
         default value is "mhi", so that the test includes all these objects.
     format : str
         format string. The default value is "pdf".
-    uid : str
-        some string to add to the filename used to store the output. Use it to
-        allow parallel execution of two tests with the same objects parameter.
     """
     from nose.tools import assert_equal
     plots = []
@@ -127,7 +124,7 @@ def _determinism_source_date_epoch(format, string, keyword=b"CreationDate"):
         format string, such as "pdf".
     string : str
         timestamp string for 2000-01-01 00:00 UTC.
-    keyword : str
+    keyword : bytes
         a string to look at when searching for the timestamp in the document
         (used in case the test fails).
     """
diff --git a/lib/matplotlib/tests/test_backend_ps.py b/lib/matplotlib/tests/test_backend_ps.py
index c2457ca3471d..7797deb01669 100644
--- a/lib/matplotlib/tests/test_backend_ps.py
+++ b/lib/matplotlib/tests/test_backend_ps.py
@@ -198,7 +198,7 @@ def test_determinism_all():
 @needs_ghostscript
 def test_determinism_all_tex():
     """Test for reproducible PS/tex output"""
-    _determinism_check(format="ps", uid="_tex", usetex=True)
+    _determinism_check(format="ps", usetex=True)
 
 
 if __name__ == '__main__':

From 1a5ada6baf3d7572fa2c0b64f5d9e2dae20db08e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alexis=20Bienven=C3=BCe?= <pado@passoire.fr>
Date: Thu, 3 Nov 2016 21:47:01 +0100
Subject: [PATCH 30/30] Typo

---
 doc/users/whats_new/reproducible_ps_pdf.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/doc/users/whats_new/reproducible_ps_pdf.rst b/doc/users/whats_new/reproducible_ps_pdf.rst
index 97585a674b50..2e8294f1e414 100644
--- a/doc/users/whats_new/reproducible_ps_pdf.rst
+++ b/doc/users/whats_new/reproducible_ps_pdf.rst
@@ -2,7 +2,7 @@ Reproducible PS and PDF output
 ------------------------------
 
 The ``SOURCE_DATE_EPOCH`` environment variable can now be used to set
-the timestamps value in the PS and PDF outputs. See
+the timestamp value in the PS and PDF outputs. See
 https://reproducible-builds.org/specs/source-date-epoch/
 
 The reproducibility of the output from the PS and PDF backends has so