Merge commit '4436f25a16'

* commit '4436f25a16':
  build: remove references to unused EXTRAOBJS variable
  lavfi: convert input/ouput list compound literals to named objects
  fate: add h263 obmc vsynth tests
  avconv: remove bogus warning when using avconv -h without parameter
  averror: explicitly define AVERROR_* values
  flashsv: propagate inflateReset() errors
  indeo4/5: remove constant parameter num_bands from wavelet recomposition
  mxfdec: return error if no segments are available in mxf_get_sorted_table_segments
  Double motion vector range for HPEL interlaced picture in proper place

Conflicts:
	libavcodec/v210dec.h
	libavfilter/af_aformat.c
	libavfilter/af_amix.c
	libavfilter/af_asyncts.c
	libavfilter/af_channelmap.c
	libavfilter/af_join.c
	libavfilter/asrc_anullsrc.c
	libavfilter/buffersrc.c
	libavfilter/f_setpts.c
	libavfilter/f_settb.c
	libavfilter/fifo.c
	libavfilter/src_movie.c
	libavfilter/vf_ass.c
	libavfilter/vf_blackframe.c
	libavfilter/vf_boxblur.c
	libavfilter/vf_delogo.c
	libavfilter/vf_drawbox.c
	libavfilter/vf_drawtext.c
	libavfilter/vf_fade.c
	libavfilter/vf_fieldorder.c
	libavfilter/vf_fps.c
	libavfilter/vf_hflip.c
	libavfilter/vf_overlay.c
	libavfilter/vf_pad.c
	libavfilter/vf_select.c
	libavfilter/vf_transpose.c
	libavfilter/vf_yadif.c
	libavfilter/vsrc_testsrc.c
	libavformat/mxfdec.c
	libavutil/error.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>

ffmpeg_opt.c

@@ -2160,7 +2160,7 @@ void show_help_default(const char *opt, const char *arg)
     const int per_file = OPT_SPEC | OPT_OFFSET | OPT_PERFILE;
     int show_advanced = 0, show_avoptions = 0;
 
-    if (opt) {
+    if (opt && *opt) {
         if (!strcmp(opt, "long"))
             show_advanced = 1;
         else if (!strcmp(opt, "full"))