FLI overflow error fix and testcase CVE-2016-0775

Tests/check_fli_overflow.py

@@ -0,0 +1,16 @@
+from helper import unittest, PillowTestCase
+from PIL import Image
+
+TEST_FILE = "Tests/images/fli_overflow.fli"
+
+
+class TestFliOverflow(PillowTestCase):
+    def test_fli_overflow(self):
+
+        # this should not crash with a malloc error or access violation
+        im = Image.open(TEST_FILE)
+        im.load()
+        
+
+if __name__ == '__main__':
+    unittest.main()

libImaging/FliDecode.c

@@ -185,7 +185,7 @@ ImagingFliDecode(Imaging im, ImagingCodecState state, UINT8* buf, int bytes)
 	    /* COPY chunk */
 	    for (y = 0; y < state->ysize; y++) {
 		UINT8* buf = (UINT8*) im->image[y];
-		memcpy(buf+x, data, state->xsize);
+		memcpy(buf, data, state->xsize);
 		data += state->xsize;
 	    }
 	    break;