Merge pull request #4620 from ElinksFr/fix-gbr-image-loading

Fix repeatedly loading .gbr

Author: radarhere

Tests/test_file_gbr.py

@@ -15,3 +15,11 @@ def test_gbr_file():
     with Image.open("Tests/images/gbr.gbr") as im:
         with Image.open("Tests/images/gbr.png") as target:
             assert_image_equal(target, im)
+
+
+def test_multiple_load_operations():
+    with Image.open("Tests/images/gbr.gbr") as im:
+        im.load()
+        im.load()
+        with Image.open("Tests/images/gbr.png") as target:
+            assert_image_equal(target, im)

src/PIL/GbrImagePlugin.py

@@ -84,6 +84,10 @@ def _open(self):
         self._data_size = width * height * color_depth
 
     def load(self):
+        if self.im:
+            # Already loaded
+            return
+
         self.im = Image.core.new(self.mode, self.size)
         self.frombytes(self.fp.read(self._data_size))