From bc00dc9f8ee8a5a68cd64c015834926a9511bf1d Mon Sep 17 00:00:00 2001
From: Thomas Robitaille <thomas.robitaille@gmail.com>
Date: Sun, 2 Nov 2014 15:16:10 +0100
Subject: [PATCH 1/3] Fixed a bug that caused rc parameters to not be reset to
 initial state if an exception happened while setting new rc parameters inside
 rc_context.

---
 lib/matplotlib/__init__.py            | 13 +++++++++----
 lib/matplotlib/tests/test_rcparams.py | 22 ++++++++++++++++++++++
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
index e07a6fd13e87..a7034c47f952 100644
--- a/lib/matplotlib/__init__.py
+++ b/lib/matplotlib/__init__.py
@@ -1249,10 +1249,15 @@ def __init__(self, rc=None, fname=None):
         self.rcdict = rc
         self.fname = fname
         self._rcparams = rcParams.copy()
-        if self.fname:
-            rc_file(self.fname)
-        if self.rcdict:
-            rcParams.update(self.rcdict)
+        try:
+            if self.fname:
+                rc_file(self.fname)
+            if self.rcdict:
+                rcParams.update(self.rcdict)
+        except:
+            # if anything goes wrong, revert rc parameters and re-raise
+            rcParams.update(self._rcparams)
+            raise
 
     def __enter__(self):
         return self
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
index 74341c6ba26c..3d0e6f3295e0 100644
--- a/lib/matplotlib/tests/test_rcparams.py
+++ b/lib/matplotlib/tests/test_rcparams.py
@@ -262,3 +262,25 @@ def test_keymaps():
     key_list = [k for k in mpl.rcParams if 'keymap' in k]
     for k in key_list:
         assert(isinstance(mpl.rcParams[k], list))
+
+
+def test_rcparams_reset_after_fail():
+
+    # There was previously a bug that meant that if rc_context failed and
+    # raised an exception due to issues in the supplied rc parameters, the
+    # global rc parameters were left in a modified state.
+
+    try:
+        from collections import OrderedDict
+    except:
+        return  # can't run this test on Python 2.6
+
+    with mpl.rc_context(rc={'text.usetex': False}):
+
+        assert mpl.rcParams['text.usetex'] is False
+
+        with assert_raises(KeyError):
+            with mpl.rc_context(rc=OrderedDict([('text.usetex', True),('test.blah', True)])):
+                pass
+
+        assert mpl.rcParams['text.usetex'] is False

From 8d3cd0c4b6e52e484c5b77ddccd8bc9424c54996 Mon Sep 17 00:00:00 2001
From: Thomas Robitaille <thomas.robitaille@gmail.com>
Date: Sun, 2 Nov 2014 17:03:48 +0100
Subject: [PATCH 2/3] Minor fixes

---
 lib/matplotlib/__init__.py            | 1 +
 lib/matplotlib/tests/test_rcparams.py | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
index a7034c47f952..6ec9edac84e0 100644
--- a/lib/matplotlib/__init__.py
+++ b/lib/matplotlib/__init__.py
@@ -1256,6 +1256,7 @@ def __init__(self, rc=None, fname=None):
                 rcParams.update(self.rcdict)
         except:
             # if anything goes wrong, revert rc parameters and re-raise
+            rcParams.clear()
             rcParams.update(self._rcparams)
             raise
 
diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
index 3d0e6f3295e0..4ba6b1b5c227 100644
--- a/lib/matplotlib/tests/test_rcparams.py
+++ b/lib/matplotlib/tests/test_rcparams.py
@@ -272,7 +272,7 @@ def test_rcparams_reset_after_fail():
 
     try:
         from collections import OrderedDict
-    except:
+    except ImportError:
         return  # can't run this test on Python 2.6
 
     with mpl.rc_context(rc={'text.usetex': False}):

From 39c3194847b6683c06066e666a896ee0edb51896 Mon Sep 17 00:00:00 2001
From: Thomas Robitaille <thomas.robitaille@gmail.com>
Date: Mon, 3 Nov 2014 10:25:49 +0100
Subject: [PATCH 3/3] raise SkipTest if not using Python >= 2.7

---
 lib/matplotlib/tests/test_rcparams.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
index 4ba6b1b5c227..ec92da9ee246 100644
--- a/lib/matplotlib/tests/test_rcparams.py
+++ b/lib/matplotlib/tests/test_rcparams.py
@@ -12,6 +12,7 @@
 from matplotlib.tests import assert_str_equal
 from matplotlib.testing.decorators import cleanup, knownfailureif
 from nose.tools import assert_true, assert_raises, assert_equal
+from nose.plugins.skip import SkipTest
 import nose
 from itertools import chain
 import numpy as np
@@ -270,10 +271,10 @@ def test_rcparams_reset_after_fail():
     # raised an exception due to issues in the supplied rc parameters, the
     # global rc parameters were left in a modified state.
 
-    try:
+    if sys.version_info[:2] >= (2, 7):
         from collections import OrderedDict
-    except ImportError:
-        return  # can't run this test on Python 2.6
+    else:
+        raise SkipTest("Test can only be run in Python >= 2.7 as it requires OrderedDict")
 
     with mpl.rc_context(rc={'text.usetex': False}):