[vlc-devel] [PATCH] demux/xiph_metadata.c: fix bug causing redudant "extra" metadata

[Filip Roséen]

The IF_EXTRACT_FMT macro is to be used in a if-else-tree, the usage of
IF_EXTRACT prior to the following if-statement did however cause the
single if-else-tree to be split up into two (causing the fallback-else
at the end to be unconditionally hit, even if another branch had already
handled the data).

This patch fixes that issue.

--

Sample usage (from xiph_metadata.c):

        IF_EXTRACT("TITLE=", Title )
        ...
        else IF_EXTRACT_ONCE("TRACKTOTAL=", TrackTotal )
        else IF_EXTRACT_ONCE("TOTALTRACKS=", TrackTotal )
        else IF_EXTRACT("DESCRIPTION=", Description )
        else IF_EXTRACT("COMMENT=", Description )
        else IF_EXTRACT("COMMENTS=", Description )
        else IF_EXTRACT("RATING=", Rating )
        else IF_EXTRACT("DATE=", Date )
        else IF_EXTRACT_FMT("LANGUAGE=", Language, p_fmt, psz_language )
        ...
        else if( ... /* fallback */ ) {
            vlc_meta_AddExtra( ... );
        }

If "TITLE=" metadata was found, we would still end up inside the
fallback since the previous implementation of IF_EXTRACT_FMT would start
a new if-else-tree.
---
 modules/demux/xiph_metadata.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/modules/demux/xiph_metadata.c b/modules/demux/xiph_metadata.c
index 2e9ecba..f8878ad 100644
--- a/modules/demux/xiph_metadata.c
+++ b/modules/demux/xiph_metadata.c
@@ -389,12 +389,15 @@ void vorbis_ParseComment( es_format_t *p_fmt, vlc_meta_t **pp_meta,
     }
 
 #define IF_EXTRACT_FMT(txt,var,fmt,target) \
-    IF_EXTRACT(txt,var)\
-    if( fmt && !strncasecmp(psz_comment, txt, strlen(txt)) )\
+    if( !strncasecmp(psz_comment, txt, strlen(txt)) ) \
+    { \
+        IF_EXTRACT(txt,var)\
+        if( fmt )\
         {\
             if ( fmt->target ) free( fmt->target );\
             fmt->target = strdup(&psz_comment[strlen(txt)]);\
-        }
+        }\
+    }
 
         IF_EXTRACT("TITLE=", Title )
         else IF_EXTRACT("ARTIST=", Artist )
-- 
2.8.2