client API: change mpv_wait_event() timeout semantics

Now a negative timeout mean an infinite timeout. This is similar to the
poll() system call. Apparently this is more intuitive and less confusing
than specifying a "very high" value as timeout if you want to wait
forever.

For callers that never pass negative timeouts, nothing changes.

libmpv/client.h

@@ -1122,7 +1122,8 @@ int mpv_request_log_messages(mpv_handle *ctx, const char *min_level);
  *
  * @param timeout Timeout in seconds, after which the function returns even if
  *                no event was received. A MPV_EVENT_NONE is returned on
- *                timeout. Values <= 0 will disable waiting.
+ *                timeout. A value of 0 will disable waiting. Negative values
+ *                will wait with an infinite timeout.
  * @return A struct containing the event ID and other data. The pointer (and
  *         fields in the struct) stay valid until the next mpv_wait_event()
  *         call, or until mpv_destroy() is called. You must not write to

player/client.c

@@ -495,6 +495,9 @@ mpv_event *mpv_wait_event(mpv_handle *ctx, double timeout)
 {
     mpv_event *event = ctx->cur_event;
 
+    if (timeout < 0)
+        timeout = 1e20;
+
     int64_t deadline = mp_add_timeout(mp_time_us(), timeout);
 
     pthread_mutex_lock(&ctx->lock);
@@ -535,7 +538,7 @@ mpv_event *mpv_wait_event(mpv_handle *ctx, double timeout)
         }
         if (ctx->queued_wakeup)
             break;
-        if (timeout <= 0)
+        if (timeout == 0)
             break;
         int r = mpthread_cond_timedwait(&ctx->wakeup, &ctx->lock, deadline);
         if (r == ETIMEDOUT)

player/lua/defaults.lua

@@ -360,7 +360,7 @@ function mp.dispatch_events(allow_wait)
         if wait == nil then
             wait = 1e20 -- infinity for all practical purposes
         end
-        if more_events then
+        if more_events or wait < 0 then
             wait = 0
         end
         -- Resume playloop - important especially if an error happened while