Capture stderr to a file instead.

anntzer · anntzer · commit 3ab7b714ed54 · 2017-03-13T14:35:13.000-07:00
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -15,6 +15,7 @@
 import re
 import shutil
 import sys
+from tempfile import TemporaryFile
 
 import numpy as np
 
@@ -132,8 +133,8 @@ def convert(old, new):
     return convert
 
 
-# Copied from https://bugs.python.org/issue25567
-_find_unsafe_bytes = re.compile(rb'[^\w@%+=:,./-]', re.ASCII).search
+# Modified from https://bugs.python.org/issue25567.
+_find_unsafe_bytes = re.compile(br'[^a-zA-Z0-9_@%+=:,./-]').search
 
 
 def _shlex_quote_bytes(b):
@@ -182,13 +183,19 @@ def __call__(self, orig, dest):
             # `--without-gui`).  Unsetting `DISPLAY` prevents this (and causes
             # GTK to crash and Inkscape to terminate, but that'll just be
             # reported as a regular exception below).
-            env["DISPLAY"] = ""
+            env.pop("DISPLAY", None)  # May already be unset.
             # Do not load any user options.
-            env["INKSCAPE_PROFILE_DIR"] = os.devnull
+            # `os.environ` needs native strings on Py2+Windows.
+            env[str("INKSCAPE_PROFILE_DIR")] = os.devnull
+            # Old versions of Inkscape (0.48.3.1, used on Travis as of now)
+            # seem to sometimes deadlock when stderr is redirected to a pipe,
+            # so we redirect it to a temporary file instead.  This is not
+            # necessary anymore as of Inkscape 0.92.1.
+            self._stderr = TemporaryFile()
             self._proc = subprocess.Popen(
                 [str("inkscape"), "--without-gui", "--shell"],
-                env=env, stdin=subprocess.PIPE,
-                stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+                stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                stderr=self._stderr, env=env)
             if not self._read_to_prompt():
                 raise OSError("Failed to start Inkscape")
 
@@ -200,16 +207,23 @@ def __call__(self, orig, dest):
             def fsencode(s):
                 return s.encode(sys.getfilesystemencoding())
 
-        orig, dest = map(_shlex_quote_bytes, map(fsencode, [orig, dest]))
-        self._proc.stdin.write(orig + b" --export-png=" + dest + b"\n")
+        orig_b, dest_b = map(_shlex_quote_bytes, map(fsencode, [orig, dest]))
+        if b"\n" in orig_b or b"\n" in dest_b:
+            # Who knows whether the current folder name has a newline, or if
+            # our encoding is even ASCII compatible...  Just fall back on the
+            # slow solution.
+            return make_external_conversion_command(lambda old, new: [
+                str('inkscape'), '-z', old, '--export-png', new])(orig, dest)
+        self._proc.stdin.write(orig_b + b" --export-png=" + dest_b + b"\n")
         self._proc.stdin.flush()
         if not self._read_to_prompt():
-            # I *guess* we should technically decode the stream using
-            # `getdefaultencoding` *except* for filenames which should be
-            # decoded using `getfilesystemencoding` but that would be a bit
-            # overkill.
+            # Inkscape's output is not localized but gtk's is, so the
+            # output stream probably has a mixed encoding.  Using
+            # `getfilesystemencoding` should at least get the filenames
+            # right...
+            self._stderr.seek(0)
             raise ImageComparisonFailure(
-                self._proc.stderr.read().decode(
+                self._stderr.read().decode(
                     sys.getfilesystemencoding(), "replace"))
 
     def __del__(self):
@@ -219,7 +233,7 @@ def __del__(self):
                 self._proc.wait()
             self._proc.stdin.close()
             self._proc.stdout.close()
-            self._proc.stderr.close()
+            self._stderr.close()
 
 
 def _update_converter():
