mkv.cpp: better handling of the seekpoint numbers

modules/demux/mkv.cpp

@@ -1459,14 +1459,15 @@ static void UpdateCurrentChapter( demux_t & demux, mtime_t i_pts )
         /* 1st, we need to know in which chapter we are */
         psz_curr_chapter = sys.editions[sys.i_current_edition].FindTimecode( i_pts );
 
-        if (sys.psz_current_chapter != NULL && psz_curr_chapter != NULL && sys.psz_current_chapter->i_seekpoint_num != psz_curr_chapter->i_seekpoint_num)
+        /* we have moved to a new chapter */
+        if (sys.psz_current_chapter != NULL && psz_curr_chapter != NULL && sys.psz_current_chapter != psz_curr_chapter)
+        {
+            if (sys.psz_current_chapter->i_seekpoint_num != psz_curr_chapter->i_seekpoint_num && psz_curr_chapter->i_seekpoint_num > 0)
             {
                 demux.info.i_update |= INPUT_UPDATE_SEEKPOINT;
                 demux.info.i_seekpoint = psz_curr_chapter->i_seekpoint_num - 1;
             }
 
-        sys.psz_current_chapter = psz_curr_chapter;
-
             if (sys.editions[sys.i_current_edition].b_ordered )
             {
                 /* TODO check if we need to silently seek to a new location in the stream (switch to another chapter) */
@@ -1474,6 +1475,8 @@ static void UpdateCurrentChapter( demux_t & demux, mtime_t i_pts )
                 /* only seek after each duration >= end timecode of the current chapter */
             }
         }
+        sys.psz_current_chapter = psz_curr_chapter;
+    }
 }
 
 static void Seek( demux_t *p_demux, mtime_t i_date, double f_percent)
@@ -3074,8 +3077,6 @@ int64_t chapter_item_t::RefreshChapters( bool b_ordered, int64_t i_prev_user_tim
         i_user_end_time = i_end_time;
     }
 
-    i_seekpoint_num = title.i_seekpoint;
-
     if (b_display_seekpoint)
     {
         seekpoint_t *sk = vlc_seekpoint_New();
@@ -3090,6 +3091,8 @@ int64_t chapter_item_t::RefreshChapters( bool b_ordered, int64_t i_prev_user_tim
         title.seekpoint[title.i_seekpoint-1] = sk;
     }
 
+    i_seekpoint_num = title.i_seekpoint;
+
     return i_user_end_time;
 }