# min-version: 0.40.0
# Backport of upstream mpv commit f74adc4243bd9e1a8ee96d187c939e6232510650
# ("opengl/context: require swap_buffers param for FenceSync"), fixes
# upstream #17217. v0.37.0 predates the refactor (commits 8854c74/
# 5ae0e0f) that introduced this regression - it used a different,
# correct external_swapchain boolean flag structure that this patch's
# field names don't match at all. Confirmed present (buggy) in v0.41.0.
--- a/video/out/opengl/context.c	2026-07-13 00:13:22.285143606 +0000
+++ b/video/out/opengl/context.c	2026-07-13 00:13:32.092351785 +0000
@@ -232,7 +232,19 @@
     if (p->opts->use_glfinish)
         gl->Finish();
 
-    if (gl->FenceSync) {
+    // yauiclient/NextPVR: backport of upstream mpv commit
+    // f74adc4243bd9e1a8ee96d187c939e6232510650 ("opengl/context: require
+    // swap_buffers param for FenceSync"), fixes #17217. Commits 8854c74/
+    // 5ae0e0f eliminated the external swapchain API vo_libmpv previously
+    // used to skip these FenceSync calls; that logic change wasn't
+    // accounted for, so vo_libmpv leaked one GLsync fence into
+    // p->vsync_fences (a heap-allocated array, not GPU-driver memory) on
+    // every single frame, since ra_gl_ctx_swap_buffers - the function
+    // that normally consumes/frees them - is never called for vo_libmpv
+    // specifically. This is exactly the embedded Render API backend
+    // (mpv_render_context_render() called repeatedly into an app-owned
+    // FBO) that yauiclient uses every frame.
+    if (gl->FenceSync && p->params.swap_buffers) {
         GLsync fence = gl->FenceSync(GL_SYNC_GPU_COMMANDS_COMPLETE, 0);
         if (fence)
             MP_TARRAY_APPEND(p, p->vsync_fences, p->num_vsync_fences, fence);