command: if only ab-loop-b is set, loop from start of file

Commit 382bafcb changed the behavior for ab-loop-a. This commit changes
ab-loop-b so that the behavior is symmetric.

Adjust the OSD rendering accordingly to the two changes.

Also fix mentions of the "ab_loop" command to the now preferred
"ab-loop".

2 files changed, 13 insertions, 8 deletions

diff --git a/player/command.c b/player/command.c
index bfdcb820d3..7f65534d84 100644
--- a/player/command.c
+++ b/player/command.c
@@ -5245,16 +5245,20 @@ void handle_ab_loop(struct MPContext *mpctx)
     struct MPOpts *opts = mpctx->opts;
 
     double now = mpctx->restart_complete ? mpctx->playback_pts : MP_NOPTS_VALUE;
-    if (now != MP_NOPTS_VALUE && opts->ab_loop[0] != MP_NOPTS_VALUE) {
+    if (now != MP_NOPTS_VALUE && (opts->ab_loop[0] != MP_NOPTS_VALUE ||
+                                  opts->ab_loop[1] != MP_NOPTS_VALUE))
+    {
+        double start = opts->ab_loop[0];
+        if (start == MP_NOPTS_VALUE)
+            start = 0;
         double end = opts->ab_loop[1];
         if (end == MP_NOPTS_VALUE)
             end = INFINITY;
-        if (ctx->prev_pts >= opts->ab_loop[0] &&
-            ctx->prev_pts < end &&
+        if (ctx->prev_pts >= start && ctx->prev_pts < end &&
             (now >= end || mpctx->stop_play == AT_END_OF_FILE))
         {
             mark_seek(mpctx);
-            queue_seek(mpctx, MPSEEK_ABSOLUTE, opts->ab_loop[0],
+            queue_seek(mpctx, MPSEEK_ABSOLUTE, start,
                        MPSEEK_EXACT, false);
         }
     }
diff --git a/player/osd.c b/player/osd.c
index 7da4a038bf..810df73719 100644
--- a/player/osd.c
+++ b/player/osd.c
@@ -362,14 +362,15 @@ void set_osd_bar_chapters(struct MPContext *mpctx, int type)
     mpctx->osd_progbar.num_stops = 0;
     double len = get_time_length(mpctx);
     if (len > 0) {
-        if (opts->ab_loop[0] != MP_NOPTS_VALUE &&
-            opts->ab_loop[1] != MP_NOPTS_VALUE)
-        {
+        if (opts->ab_loop[0] != MP_NOPTS_VALUE) {
             MP_TARRAY_APPEND(mpctx, mpctx->osd_progbar.stops,
                         mpctx->osd_progbar.num_stops, opts->ab_loop[0] / len);
+        }
+        if (opts->ab_loop[1] != MP_NOPTS_VALUE) {
             MP_TARRAY_APPEND(mpctx, mpctx->osd_progbar.stops,
                         mpctx->osd_progbar.num_stops, opts->ab_loop[1] / len);
-        } else {
+        }
+        if (mpctx->osd_progbar.stops == 0) {
             int num = get_chapter_count(mpctx);
             for (int n = 0; n < num; n++) {
                 double time = chapter_start_time(mpctx, n);