[PATCH v4 0/1] MR8742: mf: Handle start request when session is already running.

[Bernhard Kölbl (＠besentv)]

Starting the session while it's already running should not resume anything.

--
  v4: mf: Handle start request when session is already running.

https://gitlab.winehq.org/wine/wine/-/merge_requests/8742

[PATCH v4 1/1] mf: Handle start request when session is already running.

[Bernhard Kölbl]

From: Bernhard Kölbl

Signed-off-by: Bernhard Kölbl 
---
 dlls/mf/session.c  | 12 +++++++++++-
 dlls/mf/tests/mf.c | 15 +++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/dlls/mf/session.c b/dlls/mf/session.c
index 87af5b95eab..6f6c9873fc2 100644
--- a/dlls/mf/session.c
+++ b/dlls/mf/session.c
@@ -1076,15 +1076,25 @@ static void session_start(struct media_session *session, const GUID *time_format
 {
     struct media_source *source;
     struct topo_node *topo_node;
+    BOOL keep_position;
     MFTIME duration;
     HRESULT hr;
     UINT i;

+    keep_position = IsEqualGUID(time_format, &GUID_NULL) && start_position->vt == VT_EMPTY;
+
+    /* No position change - nothing to do. */
+    if (session->state == SESSION_STATE_STARTED && keep_position)
+    {
+        session_command_complete_with_event(session, MESessionStarted, S_OK, NULL);
+        return;
+    }
+
     switch (session->state)
     {
         case SESSION_STATE_PAUSED:
         case SESSION_STATE_STARTED:
-            if (!IsEqualGUID(time_format, &GUID_NULL) || start_position->vt != VT_EMPTY)
+            if (!keep_position)
             {
                 session->command_state = COMMAND_STATE_RESTARTING_SOURCES;

diff --git a/dlls/mf/tests/mf.c b/dlls/mf/tests/mf.c
index a02f2859f91..c56e59fbc6c 100644
--- a/dlls/mf/tests/mf.c
+++ b/dlls/mf/tests/mf.c
@@ -7919,6 +7919,21 @@ static void test_media_session_seek(void)

compare_object_states(&actual_object_state_record, &expected_sample_request_and_delivery_records);

+    SET_EXPECT(test_media_sink_GetPresentationClock);
+    SET_EXPECT(test_media_sink_GetStreamSinkCount);
+
+    PropVariantClear(&propvar);
+    hr = IMFMediaSession_Start(session, NULL, &propvar);
+    ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
+
+    hr = wait_media_event(session, callback, MESessionStarted, 1000, &propvar);
+    ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);
+
+    todo_wine
+    CHECK_CALLED(test_media_sink_GetPresentationClock);
+    todo_wine
+    CHECK_CALLED(test_media_sink_GetStreamSinkCount);
+
     memset(&actual_object_state_record, 0, sizeof(actual_object_state_record));
     hr = IMFMediaSession_Pause(session);
     ok(hr == S_OK, "Unexpected hr %#lx.\n", hr);

[Bernhard Kölbl (＠besentv)]

On Fri Sep 19 19:08:10 2025 +0000, Nikolay Sivov wrote:
> Could we maybe use an early return like this instead. Switch is already
> no very readable because of a number of fallthough conditions.
> [session.diff](/uploads/16f7b84f7bfcb5beb33fd4d904004a5f/session.diff)

Yeah, I applied the diff, and picked a shorter variable name. :)

[Bernhard Kölbl (＠besentv)]

v3: apply diff

[PATCH v4 0/1] MR8742: mf: Handle start request when session is already running. - approved

[Nikolay Sivov (＠nsivov)]

This merge request was approved by Nikolay Sivov.