Merge pull request #2974 from wiredfool/webp_leak

Fix memory leak when opening webp files

Tests/check_webp_leaks.py

@@ -1,38 +0,0 @@
-from __future__ import division
-from helper import unittest, PillowTestCase
-import sys
-from PIL import Image
-from io import BytesIO
-
-# Limits for testing the leak
-mem_limit = 16  # max increase in MB
-iterations = 5000
-test_file = "Tests/images/hopper.webp"
-
-
-@unittest.skipIf(sys.platform.startswith('win32'), "requires Unix or MacOS")
-class TestWebPLeaks(PillowTestCase):
-
-    def setUp(self):
-        try:
-            from PIL import _webp
-        except ImportError:
-            self.skipTest('WebP support not installed')
-
-    def _get_mem_usage(self):
-        from resource import getpagesize, getrusage, RUSAGE_SELF
-        mem = getrusage(RUSAGE_SELF).ru_maxrss
-        return mem * getpagesize() / 1024 / 1024
-
-    def test_leak_load(self):
-        with open(test_file, 'rb') as f:
-            im_data = f.read()
-        start_mem = self._get_mem_usage()
-        for _ in range(iterations):
-            with Image.open(BytesIO(im_data)) as im:
-                im.load()
-            mem = (self._get_mem_usage() - start_mem)
-            self.assertLess(mem, mem_limit, msg='memory usage limit exceeded')
-
-if __name__ == '__main__':
-    unittest.main()

Tests/test_webp_leaks.py

@@ -0,0 +1,25 @@
+from helper import unittest, PillowLeakTestCase
+from PIL import Image, features
+from io import BytesIO
+
+test_file = "Tests/images/hopper.webp"
+
+@unittest.skipUnless(features.check('webp'), "WebP is not installed")
+class TestWebPLeaks(PillowLeakTestCase):
+
+    mem_limit = 3 * 1024 # kb
+    iterations = 100
+
+    def test_leak_load(self):
+        with open(test_file, 'rb') as f:
+            im_data = f.read()
+
+        def core():
+            with Image.open(BytesIO(im_data)) as im:
+                im.load()
+
+        self._test_leak(core)
+
+
+if __name__ == '__main__':
+    unittest.main()

src/_webp.c

@@ -410,6 +410,7 @@ PyObject* _anim_decoder_get_next(PyObject* self, PyObject* args)
     uint8_t* buf;
     int timestamp;
     PyObject* bytes;
+    PyObject* ret;
     WebPAnimDecoderObject* decp = (WebPAnimDecoderObject*)self;
 
     if (!WebPAnimDecoderGetNext(decp->dec, &buf, &timestamp)) {
@@ -419,7 +420,11 @@ PyObject* _anim_decoder_get_next(PyObject* self, PyObject* args)
 
     bytes = PyBytes_FromStringAndSize((char *)buf,
         decp->info.canvas_width * 4 * decp->info.canvas_height);
-    return Py_BuildValue("Si", bytes, timestamp);
+
+    ret = Py_BuildValue("Si", bytes, timestamp);
+
+    Py_DECREF(bytes);
+    return ret;
 }
 
 PyObject* _anim_decoder_has_more_frames(PyObject* self, PyObject* args)