MNT: Be more defensive about pre-reading into BytesIO

tacaswell · timhoffm · web-flow · commit 55ba612bb6d1 · 2020-08-05T20:09:02.000-04:00
Co-authored-by: Tim Hoffmann &lt;2836374+timhoffm@users.noreply.github.com&gt;
diff --git a/lib/matplotlib/image.py b/lib/matplotlib/image.py
@@ -1473,7 +1473,11 @@ def imread(fname, format=None):
         parsed = urllib.parse.urlparse(fname)
         if len(parsed.scheme) > 1:  # Pillow doesn't handle URLs directly.
             with urllib.request.urlopen(fname) as response:
-                return imread(BytesIO(response.read()), format=ext)
+                try:
+                    response.seek(0)
+                except (AttributeError, io.UnsupportedOperation):
+                    response = BytesIO(response.read())
+                return imread(response, format=ext)
     with img_open(fname) as image:
         return (_pil_png_to_float_array(image)
                 if isinstance(image, PIL.PngImagePlugin.PngImageFile) else
