pngdec: use png_error() as recommended by libpng docs to signal an error

Without that the element loops endlessly on broekn pngs. Fixes #634314

diff --git a/ext/libpng/gstpngdec.c b/ext/libpng/gstpngdec.c
index ae9460d..47090e5 100644 (file)
--- a/ext/libpng/gstpngdec.c
+++ b/ext/libpng/gstpngdec.c
@@ -343,6 +343,7 @@ pause:
           ("stream stopped, reason %s", gst_flow_get_name (ret)));
       gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());
     }
+    png_error (png_ptr, "Internal data stream error.");
     return;
   }
 short_buffer: