Fix test_imshow_pil on Windows.

anntzer · anntzer · commit 7930b4379327 · 2019-06-02T21:22:26.000+02:00
test_imshow_pil currently fails on Windows, but this was not detected
because PIL is not installed on the Appveyor CI so the test is skipped.
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
@@ -119,13 +119,17 @@ def test_image_python_io():
 def test_imshow_pil(fig_test, fig_ref):
     style.use("default")
     PIL = pytest.importorskip("PIL")
-    png_path = Path(__file__).parent / "baseline_images/pngsuite/basn3p04.png"
-    tiff_path = Path(__file__).parent / "baseline_images/test_image/uint16.tif"
+    # Pillow<=6.0 fails to open pathlib.Paths on Windows (pillow#3823), and
+    # Matplotlib's builtin png opener doesn't handle them either.
+    png_path = str(
+        Path(__file__).parent / "baseline_images/pngsuite/basn3p04.png")
+    tiff_path = str(
+        Path(__file__).parent / "baseline_images/test_image/uint16.tif")
     axs = fig_test.subplots(2)
     axs[0].imshow(PIL.Image.open(png_path))
     axs[1].imshow(PIL.Image.open(tiff_path))
     axs = fig_ref.subplots(2)
-    axs[0].imshow(plt.imread(str(png_path)))
+    axs[0].imshow(plt.imread(png_path))
     axs[1].imshow(plt.imread(tiff_path))
 
 
