Run encoder cleanup method after errors as well

Author: radarhere

Tests/test_imagefile.py

@@ -200,6 +200,9 @@ class MockPyEncoder(ImageFile.PyEncoder):
     def encode(self, buffer):
         return 1, 1, b""
 
+    def cleanup(self):
+        self.cleanup_called = True
+
 
 xoff, yoff, xsize, ysize = 10, 20, 100, 100
 
@@ -327,10 +330,12 @@ def test_negsize(self):
         im = MockImageFile(buf)
 
         fp = BytesIO()
+        self.encoder.cleanup_called = False
         with pytest.raises(ValueError):
             ImageFile._save(
                 im, fp, [("MOCK", (xoff, yoff, -10, yoff + ysize), 0, "RGB")]
             )
+        assert self.encoder.cleanup_called
 
         with pytest.raises(ValueError):
             ImageFile._save(

src/PIL/ImageFile.py

@@ -503,36 +503,40 @@ def _save(im, fp, tile, bufsize=0):
         # compress to Python file-compatible object
         for e, b, o, a in tile:
             e = Image._getencoder(im.mode, e, a, im.encoderconfig)
-            if o > 0:
-                fp.seek(o)
-            e.setimage(im.im, b)
-            if e.pushes_fd:
-                e.setfd(fp)
-                l, s = e.encode_to_pyfd()
-            else:
-                while True:
-                    l, s, d = e.encode(bufsize)
-                    fp.write(d)
-                    if s:
-                        break
-            if s < 0:
-                raise OSError(f"encoder error {s} when writing image file") from exc
-            e.cleanup()
+            try:
+                if o > 0:
+                    fp.seek(o)
+                e.setimage(im.im, b)
+                if e.pushes_fd:
+                    e.setfd(fp)
+                    l, s = e.encode_to_pyfd()
+                else:
+                    while True:
+                        l, s, d = e.encode(bufsize)
+                        fp.write(d)
+                        if s:
+                            break
+                if s < 0:
+                    raise OSError(f"encoder error {s} when writing image file") from exc
+            finally:
+                e.cleanup()
     else:
         # slight speedup: compress to real file object
         for e, b, o, a in tile:
             e = Image._getencoder(im.mode, e, a, im.encoderconfig)
-            if o > 0:
-                fp.seek(o)
-            e.setimage(im.im, b)
-            if e.pushes_fd:
-                e.setfd(fp)
-                l, s = e.encode_to_pyfd()
-            else:
-                s = e.encode_to_file(fh, bufsize)
-            if s < 0:
-                raise OSError(f"encoder error {s} when writing image file")
-            e.cleanup()
+            try:
+                if o > 0:
+                    fp.seek(o)
+                e.setimage(im.im, b)
+                if e.pushes_fd:
+                    e.setfd(fp)
+                    l, s = e.encode_to_pyfd()
+                else:
+                    s = e.encode_to_file(fh, bufsize)
+                if s < 0:
+                    raise OSError(f"encoder error {s} when writing image file")
+            finally:
+                e.cleanup()
     if hasattr(fp, "flush"):
         fp.flush()