Deprecate support for running svg converter from path contaning newline.

anntzer · anntzer · commit 21495b31ca6e · 2020-04-22T12:27:00.000+02:00
Inkscape's batch mode doesn't handle newlines(!) in file names, which
tbh doesn't seem to be a too big restriction in practice.  Right now we
fallback on a specific path to handle that case, but I doubt that it is
really hit, given that the batch ghostscript converter likely has the
same limitation and no one complained about it for two years.
diff --git a/doc/api/api_changes_3.3/deprecations.rst b/doc/api/api_changes_3.3/deprecations.rst
@@ -465,3 +465,7 @@ keyword-only, consistently with ``Colorbar``.
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Passing ``None`` as either the ``radius`` or ``startangle`` of an `.Axes.pie`
 is deprecated; use the explicit defaults of 1 and 0, respectively, instead.
+
+``testing.compare.make_external_conversion_command``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+... is deprecated.
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -1,6 +1,5 @@
 """
-Provides a collection of utilities for comparing (image) results.
-
+Utilities for comparing image results.
 """
 
 import atexit
@@ -17,6 +16,7 @@
 import PIL
 
 import matplotlib as mpl
+from matplotlib import cbook
 from matplotlib.testing.exceptions import ImageComparisonFailure
 
 __all__ = ['compare_images', 'comparable_formats']
@@ -55,6 +55,7 @@ def get_file_hash(path, block_size=2 ** 20):
     return md5.hexdigest()
 
 
+@cbook.deprecated("3.3")
 def make_external_conversion_command(cmd):
     def convert(old, new):
         cmdline = cmd(old, new)
@@ -194,6 +195,10 @@ def __call__(self, orig, dest):
             # our encoding is even ASCII compatible...  Just fall back on the
             # slow solution (Inkscape uses `fgets` so it will always stop at a
             # newline).
+            cbook.warn_deprecated(
+                "3.3", message="Support for converting files from paths "
+                "containing a newline is deprecated since %(since)s and "
+                "support will be removed %(removal)s")
             return make_external_conversion_command(lambda old, new: [
                 'inkscape', '-z', old, '--export-png', new])(orig, dest)
         self._proc.stdin.write(orig_b + b" --export-png=" + dest_b + b"\n")
