gnu: python-pillow: Fix test failures with freetype-2.7.

* gnu/packages/patches/python-pillow-freetype-2.7-test-failure.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/python.scm (python-pillow, python2-pillow)[source]: Use it.

2 files changed, 76 insertions, 0 deletions

diff --git a/gnu/packages/patches/python-pillow-freetype-2.7-test-failure.patch b/gnu/packages/patches/python-pillow-freetype-2.7-test-failure.patch
new file mode 100644
index 0000000000..18bc30bc79
--- /dev/null
+++ b/gnu/packages/patches/python-pillow-freetype-2.7-test-failure.patch
@@ -0,0 +1,75 @@
+Fix some test failures when building with freetype-2.7.
+
+https://github.com/python-pillow/Pillow/issues/2116
+https://github.com/python-pillow/Pillow/pull/2286
+
+Patch copied from upstream source repository:
+
+https://github.com/python-pillow/Pillow/commit/acf68c835c93ba144f83198306aa7e6082a43f43
+
+From acf68c835c93ba144f83198306aa7e6082a43f43 Mon Sep 17 00:00:00 2001
+From: hugovk <hugovk@users.noreply.github.com>
+Date: Mon, 12 Dec 2016 15:16:43 +0200
+Subject: [PATCH] Increase epsilon for FreeType 2.7
+
+---
+ Tests/test_imagefont.py | 15 ++++++++++-----
+ 1 file changed, 10 insertions(+), 5 deletions(-)
+
+diff --git a/Tests/test_imagefont.py b/Tests/test_imagefont.py
+index de89ac92..5207dce3 100644
+--- a/Tests/test_imagefont.py
++++ b/Tests/test_imagefont.py
+@@ -125,7 +125,9 @@ try:
+ 
+             target = 'Tests/images/rectangle_surrounding_text.png'
+             target_img = Image.open(target)
+-            self.assert_image_similar(im, target_img, .5)
++
++            # Epsilon ~.5 fails with FreeType 2.7
++            self.assert_image_similar(im, target_img, 2.5)
+ 
+         def test_render_multiline(self):
+             im = Image.new(mode='RGB', size=(300, 100))
+@@ -144,7 +146,7 @@ try:
+             # some versions of freetype have different horizontal spacing.
+             # setting a tight epsilon, I'm showing the original test failure
+             # at epsilon = ~38.
+-            self.assert_image_similar(im, target_img, .5)
++            self.assert_image_similar(im, target_img, 6.2)
+ 
+         def test_render_multiline_text(self):
+             ttf = ImageFont.truetype(FONT_PATH, FONT_SIZE)
+@@ -158,7 +160,8 @@ try:
+             target = 'Tests/images/multiline_text.png'
+             target_img = Image.open(target)
+ 
+-            self.assert_image_similar(im, target_img, .5)
++            # Epsilon ~.5 fails with FreeType 2.7
++            self.assert_image_similar(im, target_img, 6.2)
+ 
+             # Test that text() can pass on additional arguments
+             # to multiline_text()
+@@ -178,7 +181,8 @@ try:
+                 target = 'Tests/images/multiline_text'+ext+'.png'
+                 target_img = Image.open(target)
+ 
+-                self.assert_image_similar(im, target_img, .5)
++                # Epsilon ~.5 fails with FreeType 2.7
++                self.assert_image_similar(im, target_img, 6.2)
+ 
+         def test_unknown_align(self):
+             im = Image.new(mode='RGB', size=(300, 100))
+@@ -227,7 +231,8 @@ try:
+             target = 'Tests/images/multiline_text_spacing.png'
+             target_img = Image.open(target)
+ 
+-            self.assert_image_similar(im, target_img, .5)
++            # Epsilon ~.5 fails with FreeType 2.7
++            self.assert_image_similar(im, target_img, 6.2)
+ 
+         def test_rotated_transposed_font(self):
+             img_grey = Image.new("L", (100, 100))
+-- 
+2.12.0
+
diff --git a/gnu/packages/python.scm b/gnu/packages/python.scm
index 96c4245384..1903247d77 100644
--- a/gnu/packages/python.scm
+++ b/gnu/packages/python.scm
@@ -4537,6 +4537,7 @@ services for your Python modules and applications.")
      (origin
        (method url-fetch)
        (uri (pypi-uri "Pillow" version))
+       (patches (search-patches "python-pillow-freetype-2.7-test-failure.patch"))
        (sha256
         (base32
          "0xkv0p1d73gz0a1qaasf0ai4262g8f334j07vd60bjrxs2wr3nmj"))))