gst: Don't assume that get_current_caps() returns non-NULL caps after has_current_caps()

Remove calls to gst_pad_has_current_caps() which then go on to call
gst_pad_get_current_caps() as the caps can go to NULL in between. Instead just
use gst_pad_get_current_caps() and check for NULL.

https://bugzilla.gnome.org/show_bug.cgi?id=759539

ext/flac/gstflacenc.c

@@ -766,9 +766,8 @@ gst_flac_enc_getcaps (GstAudioEncoder * enc, GstCaps * filter)
 
   pad = GST_AUDIO_ENCODER_SINK_PAD (enc);
 
-  if (gst_pad_has_current_caps (pad)) {
   ret = gst_pad_get_current_caps (pad);
-  } else {
+  if (ret == NULL) {
     ret = gst_pad_get_pad_template_caps (pad);
   }
 
@@ -1281,9 +1280,8 @@ gst_flac_enc_sink_query (GstAudioEncoder * enc, GstQuery * query)
     case GST_QUERY_ACCEPT_CAPS:{
       GstCaps *acceptable, *caps;
 
-      if (gst_pad_has_current_caps (pad)) {
       acceptable = gst_pad_get_current_caps (pad);
-      } else {
+      if (acceptable == NULL) {
         acceptable = gst_pad_get_pad_template_caps (pad);
       }
 

gst/flv/gstflvmux.c

@@ -830,6 +830,7 @@ tags:
 
   if (mux->have_video) {
     GstPad *video_pad = NULL;
+    GstCaps *caps = NULL;
     GstFlvPad *cpad;
     GSList *l = mux->collect->data;
 
@@ -841,8 +842,11 @@ tags:
       }
     }
 
-    if (video_pad && gst_pad_has_current_caps (video_pad)) {
+    if (video_pad) {
-      GstCaps *caps;
+      caps = gst_pad_get_current_caps (video_pad);
+    }
+
+    if (caps != NULL) {
       GstStructure *s;
       gint size;
       gint num, den;
@@ -855,7 +859,6 @@ tags:
       script_tag = gst_buffer_append (script_tag, tmp);
       tags_written++;
 
-      caps = gst_pad_get_current_caps (video_pad);
       s = gst_caps_get_structure (caps, 0);
       gst_caps_unref (caps);
 

gst/imagefreeze/gstimagefreeze.c

@@ -265,8 +265,8 @@ gst_image_freeze_sink_getcaps (GstImageFreeze * self, GstCaps * filter)
   GstPad *pad;
 
   pad = self->sinkpad;
-  if (gst_pad_has_current_caps (pad)) {
   ret = gst_pad_get_current_caps (pad);
+  if (ret != NULL) {
     goto done;
   }
 

gst/rtp/gstrtph264depay.c

@@ -267,6 +267,7 @@ gst_rtp_h264_set_src_caps (GstRtpH264Depay * rtph264depay)
 {
   gboolean res;
   GstCaps *srccaps;
+  GstCaps *old_caps;
 
   if (!rtph264depay->byte_stream &&
       (!rtph264depay->new_codec_data ||
@@ -397,10 +398,10 @@ gst_rtp_h264_set_src_caps (GstRtpH264Depay * rtph264depay)
   }
 
 
-  if (gst_pad_has_current_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (rtph264depay))) {
+  old_caps =
-    GstCaps *old_caps =
       gst_pad_get_current_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (rtph264depay));
 
+  if (old_caps != NULL) {
     /* Only update the caps if they are not equal. For
      * AVC we don't update caps if only the codec_data
      * changes. This is the same behaviour as in h264parse

gst/shapewipe/gstshapewipe.c

@@ -329,8 +329,9 @@ gst_shape_wipe_video_sink_getcaps (GstShapeWipe * self, GstPad * pad,
 {
   GstCaps *templ, *ret, *tmp;
 
-  if (gst_pad_has_current_caps (pad))
+  ret = gst_pad_get_current_caps (pad);
-    return gst_pad_get_current_caps (pad);
+  if (ret != NULL)
+    return ret;
 
   templ = gst_pad_get_pad_template_caps (pad);
   tmp = gst_pad_peer_query_caps (self->srcpad, NULL);
@@ -451,8 +452,9 @@ gst_shape_wipe_mask_sink_getcaps (GstShapeWipe * self, GstPad * pad,
   GstCaps *ret, *tmp, *tcaps;
   guint i, n;
 
-  if (gst_pad_has_current_caps (pad))
+  ret = gst_pad_get_current_caps (pad);
-    return gst_pad_get_current_caps (pad);
+  if (ret != NULL)
+    return ret;
 
   tcaps = gst_pad_get_pad_template_caps (self->video_sinkpad);
   tmp = gst_pad_peer_query_caps (self->video_sinkpad, NULL);
@@ -535,10 +537,13 @@ gst_shape_wipe_src_getcaps (GstPad * pad, GstCaps * filter)
   GstShapeWipe *self = GST_SHAPE_WIPE (gst_pad_get_parent (pad));
   GstCaps *templ, *ret, *tmp;
 
-  if (gst_pad_has_current_caps (pad))
+  ret = gst_pad_get_current_caps (pad);
-    return gst_pad_get_current_caps (pad);
+  if (ret != NULL)
-  else if (gst_pad_has_current_caps (self->video_sinkpad))
+    return ret;
-    return gst_pad_get_current_caps (self->video_sinkpad);
+
+  ret = gst_pad_get_current_caps (self->video_sinkpad);
+  if (ret != NULL)
+    return ret;
 
   templ = gst_pad_get_pad_template_caps (self->video_sinkpad);
   tmp = gst_pad_peer_query_caps (self->video_sinkpad, NULL);

gst/videocrop/gstaspectratiocrop.c

@@ -464,9 +464,11 @@ gst_aspect_ratio_crop_set_property (GObject * object, guint prop_id,
 
   if (recheck) {
     GstCaps *caps = gst_pad_get_current_caps (aspect_ratio_crop->sink);
+    if (caps != NULL) {
       gst_aspect_ratio_crop_set_caps (aspect_ratio_crop, caps);
       gst_caps_unref (caps);
     }
+  }
 }
 
 static void