Add track marks when restarting external processes. (#2873)

Fixes: #2872

src/core/stream/generator.ml

@@ -258,6 +258,7 @@ let fill gen =
           in
           let len = min (_frame_remaining frame) available in
           let pos = _frame_position frame in
+          let new_pos = pos + len in
           gen.content <-
             Frame_base.Fields.mapi
               (fun field content ->
@@ -266,10 +267,13 @@ let fill gen =
                 in
                 (* TODO: make this append after after switch to immutable content. *)
                 (match field with
-                  (* Remove the first break in rem *)
+                  (* Remove the track mark if it is was used to compute remaining and it's not
+                     at frame boundaries. *)
                   | f when f = Frame_base.Fields.track_marks -> (
                       match Content.Track_marks.get_data rem with
-                        | _ :: d -> Content.Track_marks.set_data rem d
+                        | 0 :: d when new_pos <> Lazy.force Frame_settings.size
+                          ->
+                            Content.Track_marks.set_data rem d
                         | _ -> ())
                   | f when f = Frame_base.Fields.metadata ->
                       (* For metadata, it is expected that we only add new metadata and do not replace
@@ -291,5 +295,5 @@ let fill gen =
                         pos len);
                 rem)
               gen.content;
-          _add_track_mark ~pos:(pos + len) frame)
+          _add_track_mark ~pos:new_pos frame)
         ())

src/core/tools/external_input.ml

@@ -57,6 +57,7 @@ class virtual base ~name ~restart ~restart_on_error ~on_data ?read_header
           `Continue
       in
       let on_stop status =
+        Generator.add_track_mark self#buffer;
         header_read <- false;
         match status with
           | `Status (Unix.WEXITED 0) -> restart

tests/regression/GH2871.liq

@@ -3,7 +3,7 @@ def f() =
   s = bpm(s)
   clock.assign_new(sync="none",[s])
   output.dummy(fallible=true, s)
-  thread.run(delay=0.1, {if s.bpm() != 0. then test.pass() else test.fail () end})
+  thread.run(delay=0.2, {if s.bpm() != 0. then test.pass() else test.fail () end})
 end
 
 test.check(f)

tests/regression/GH2872.liq

@@ -0,0 +1,11 @@
+def f() =
+  track_count = ref(0)
+  s = input.external.rawaudio("ffmpeg -re -f lavfi -i sine=frequency=1000 -t 1 -ac 2 -f s16le -", restart=true, buffer=1.)
+  s.on_track(fun (_) -> begin
+    track_count := !track_count + 1
+    if !track_count > 3 then test.pass() end
+  end)
+  output.dummy(fallible=true,s)
+end
+
+test.check(f)