use queue for comitted pending surface states like proto says

"The content update is placed in a queue until it becomes active." - wl_surface::commit

Author: ikalco

src/protocols/core/Compositor.cpp

@@ -115,6 +115,7 @@ CWLSurfaceResource::CWLSurfaceResource(SP<CWlSurface> resource_) : resource(reso
 
         events.precommit.emit();
         if (pending.rejected) {
+            pending.rejected = false;
             dropPendingBuffer();
             return;
         }
@@ -129,15 +130,20 @@ CWLSurfaceResource::CWLSurfaceResource(SP<CWlSurface> resource_) : resource(reso
         }
 
         // save state while we wait for buffer to become ready
-        const auto& state = pendingStates.emplace_back(makeUnique<SSurfaceState>(pending));
+        const auto& state = pendingStates.emplace(makeUnique<SSurfaceState>(pending));
         pending.reset();
 
         auto whenReadable = [this, surf = self, state = WP<SSurfaceState>(pendingStates.back())] {
             if (!surf || state.expired())
                 return;
 
-            surf->commitState(*state);
-            std::erase(pendingStates, state);
+            while (!pendingStates.empty() && pendingStates.front() != state) {
+                commitState(*pendingStates.front());
+                pendingStates.pop();
+            }
+
+            commitState(*pendingStates.front());
+            pendingStates.pop();
         };
 
         if (state->updated.acquire) {

src/protocols/core/Compositor.hpp

@@ -9,6 +9,7 @@
 */
 
 #include <vector>
+#include <queue>
 #include <cstdint>
 #include "../WaylandProtocol.hpp"
 #include "../../render/Texture.hpp"
@@ -87,7 +88,7 @@ class CWLSurfaceResource {
     } events;
 
     SSurfaceState                          current, pending;
-    std::vector<UP<SSurfaceState>>         pendingStates;
+    std::queue<UP<SSurfaceState>>          pendingStates;
 
     std::vector<SP<CWLCallbackResource>>   callbacks;
     WP<CWLSurfaceResource>                 self;