FIX: fix reading from http/https urls via imread

tacaswell · timhoffm · tacaswell · commit 980c64988fd3 · 2020-08-05T20:12:25.000-04:00
closes #18129 Co-authored-by: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
@@ -1468,10 +1468,16 @@ def imread(fname, format=None):
     img_open = (
         PIL.PngImagePlugin.PngImageFile if ext == 'png' else PIL.Image.open)
     if isinstance(fname, str):
+        import io
+        from urllib import request
+
         parsed = urllib.parse.urlparse(fname)
         if len(parsed.scheme) > 1:  # Pillow doesn't handle URLs directly.
-            from urllib import request
-            with urllib.request.urlopen(fname) as response:
+            with request.urlopen(fname) as response:
+                try:
+                    response.seek(0)
+                except (AttributeError, io.UnsupportedOperation):
+                    response = io.BytesIO(response.read())
                 return imread(response, format=ext)
     with img_open(fname) as image:
         return (_pil_png_to_float_array(image)
diff --git a/lib/matplotlib/testing/conftest.py b/lib/matplotlib/testing/conftest.py
@@ -16,6 +16,7 @@ def pytest_configure(config):
         ("markers", "style: Set alternate Matplotlib style temporarily."),
         ("markers", "baseline_images: Compare output against references."),
         ("markers", "pytz: Tests that require pytz to be installed."),
+        ("markers", "network: Tests that reachout to the network."),
         ("filterwarnings", "error"),
     ]:
         config.addinivalue_line(key, value)
diff --git a/lib/matplotlib/tests/test_image.py b/lib/matplotlib/tests/test_image.py
@@ -1118,3 +1118,9 @@ def test_exact_vmin():
 
     # check than the RBGA values are the same
     assert np.all(from_image == direct_computation)
+
+
+@pytest.mark.network
+@pytest.mark.flaky
+def test_https_imread_smoketest():
+    v = mimage.imread('https://matplotlib.org/1.5.0/_static/logo2.png')
