Merge pull request #3683 from radarhere/exclusive

Only close original fp in __del__ and __exit__ if original fp is exclusive

Tests/test_image.py

@@ -532,6 +532,18 @@ def test_no_resource_warning_on_save(self):
         with Image.open(test_file) as im:
             self.assert_warning(None, im.save, temp_file)
 
+    def test_load_on_nonexclusive_multiframe(self):
+        with open("Tests/images/frozenpond.mpo", "rb") as fp:
+            def act(fp):
+                im = Image.open(fp)
+                im.load()
+            act(fp)
+
+            with Image.open(fp) as im:
+                im.load()
+
+            self.assertFalse(fp.closed)
+
 
 class MockEncoder(object):
     pass

src/PIL/Image.py

@@ -578,11 +578,11 @@ def __enter__(self):
         return self
 
     def __exit__(self, *args):
-        if hasattr(self, "_close__fp"):
-            self._close__fp()
-        if (hasattr(self, 'fp') and hasattr(self, '_exclusive_fp')
-           and self.fp and self._exclusive_fp):
-            self.fp.close()
+        if hasattr(self, 'fp') and getattr(self, '_exclusive_fp', False):
+            if hasattr(self, "_close__fp"):
+                self._close__fp()
+            if self.fp:
+                self.fp.close()
         self.fp = None
 
     def close(self):

src/PIL/WebPImagePlugin.py

@@ -186,7 +186,7 @@ def _save_all(im, fp, filename):
     # will preserve non-alpha modes
     total = 0
     for ims in [im]+append_images:
-        total += 1 if not hasattr(ims, "n_frames") else ims.n_frames
+        total += getattr(ims, "n_frames", 1)
     if total == 1:
         _save(im, fp, filename)
         return
@@ -254,10 +254,7 @@ def _save_all(im, fp, filename):
     try:
         for ims in [im]+append_images:
             # Get # of frames in this image
-            if not hasattr(ims, "n_frames"):
-                nfr = 1
-            else:
-                nfr = ims.n_frames
+            nfr = getattr(ims, "n_frames", 1)
 
             for idx in range(nfr):
                 ims.seek(idx)