demux/subtitle: Fix wrong ASS header parsing

After optimization in 6cccd64dacf431e1c33877e131b09ff906c85972,
complete ASS header was discarded for some subtitles.

close #12733

diff --git a/modules/demux/subtitle.c b/modules/demux/subtitle.c
index 1b22c7db4756a629a91d8ed93f3f478e209d342a..d8b6dc51504ee380b3425433c8af9bb77217e670 100644 (file)
--- a/modules/demux/subtitle.c
+++ b/modules/demux/subtitle.c
@@ -1156,6 +1156,9 @@ static int  ParseSSA( demux_t *p_demux, subtitle_t *p_subtitle,
         free( psz_text );
 
         /* All the other stuff we add to the header field */
+        if( header_len == 0 && p_sys->psz_header )
+            header_len = strlen( p_sys->psz_header );
+
         size_t s_len = strlen( s );
         p_sys->psz_header = realloc_or_free( p_sys->psz_header, header_len + s_len + 2 );
         if( !p_sys->psz_header )