[Fix] (Espryt): keep the live-map question in the handle arm's draw-clean probe instead of a record field P3a pins false

MobileGL/MG_Backend/DirectGLES/DirectGLES.cpp

@@ -612,7 +612,10 @@ namespace MobileGL::MG_Backend::DirectGLES {
                     Bool allClean = true;
                     for (Uint i = 0; i < memo->count; ++i) {
                         auto& entry = memo->entries[i];
-                        if (IsBufferDrawCleanByHandle(entry.handle, entry.resource)) continue;
+                        // entry.frontend is the same object the legacy arm probes and is kept
+                        // alive by the VAO attribute's SharedPtr for as long as this memo is
+                        // valid; it answers the live-map question no record carries in P3a.
+                        if (IsBufferDrawCleanByHandle(entry.handle, entry.resource, entry.frontend)) continue;
                         allClean = false;
                         entry.resource =
                             EnsureBufferResource(currentVAOObject->GetAttribute(entry.attribIndex).Buffer);
@@ -787,7 +790,8 @@ namespace MobileGL::MG_Backend::DirectGLES {
                         if (memo && memo->iboHandle == iboHandle && memo->iboCleanEpoch == bufferEpoch) {
                             // probed fully clean at this epoch; nothing can have dirtied it
                         } else if (memo && memo->iboHandle == iboHandle &&
-                                   IsBufferDrawCleanByHandle(iboHandle, memo->iboResource)) {
+                                   IsBufferDrawCleanByHandle(iboHandle, memo->iboResource,
+                                                             possibleIBO.get())) {
                             memo->iboCleanEpoch = bufferEpoch;
                         } else {
                             auto* resource = EnsureBufferResource(possibleIBO);

MobileGL/MG_Backend/DirectGLES/Managers.cpp

@@ -2426,13 +2426,25 @@ namespace MobileGL::MG_Backend::DirectGLES {
         //   identity      the slot table's twin at this handle, not GetBackendResource()
         //   size          record.Desc.Width, not GetSize()
         //   freshness     record.Serial vs syncedChangeSerial, not GetChangeSerial()
-        //   map state     record.HasLiveHostWrites, not IsMapped()
+        //   map state     record.HasLiveHostWrites AND the frontend's IsMapped() - see below
         //   the rest      unchanged, and server-side to begin with
         //
         // HasLiveHostWrites is ALWAYS FALSE in P3a and is written by nobody; it is here so the
         // phase that pushes persistent-mapped host writes can set it with no new record kind,
         // and the assertion below is what stops that phase landing a silent semantic change.
-        Bool IsBufferDrawCleanByHandle(MG_Pipe::MGPipeHandle res, const GLESBufferResource* resource) {
+        //
+        // BECAUSE it is pinned false, it CANNOT stand in for the frontend's IsMapped() yet, and
+        // the probe still asks the object: an EMULATED (non-adopted) persistent map - under the
+        // 16 MiB adoption threshold, or with DisableLargeBufferAdoption, or with no
+        // EXT_buffer_storage - mutates the client's shadow with no call, no serial and no epoch,
+        // which is the entire reason the legacy probe asks a map question instead of a serial
+        // one. Answering only HasLiveHostWrites made such a buffer read draw-clean forever, so
+        // SyncPersistentMappedRange (D-N keeps it on the ensure path for all of P3a) was never
+        // reached again and the frame drew the last uploaded bytes with no diagnostic anywhere.
+        // The frontend read retires the moment P5 gives HasLiveHostWrites a producer, and it is
+        // the last frontend read in this function.
+        Bool IsBufferDrawCleanByHandle(MG_Pipe::MGPipeHandle res, const GLESBufferResource* resource,
+                                       const MG_State::GLState::BufferObject* frontend) {
             if (!resource) return false;
             const auto* twin = g_backendBufferResources.FindByHandle(res);
             if (twin == nullptr || twin->get() != resource) return false;
@@ -2448,6 +2460,11 @@ namespace MobileGL::MG_Backend::DirectGLES {
                             "MGPipeResourceRecord::HasLiveHostWrites is set, but P3a has no producer for it");
 #endif
             if (record->HasLiveHostWrites) return false;
+            // The same question the legacy arm asks at this exact point in the order, for the
+            // reason written at the top of this function. A null object is the "no frontend to
+            // ask" case (nothing reaches this probe without one today) and is treated as "not
+            // mapped", which is what the record already says.
+            if (frontend != nullptr && frontend->IsMapped()) return false;
             if (resource->pendingRespecify || !resource->storageInitialized) return false;
             if (!resource->pendingRanges.empty()) return false;
             if (resource->storageSize != static_cast<SizeT>(record->Desc.Width)) return false;
@@ -2458,7 +2475,7 @@ namespace MobileGL::MG_Backend::DirectGLES {
         Bool IsBufferDrawClean(const MG_State::GLState::BufferObject* frontend, const GLESBufferResource* resource) {
 #if MOBILEGL_PIPE_PUSH
             if (ResourceSubsystemEnabled()) {
-                return IsBufferDrawCleanByHandle(HandleOfBuffer(frontend), resource);
+                return IsBufferDrawCleanByHandle(HandleOfBuffer(frontend), resource, frontend);
             }
 #endif
             // Identity first: a respecify path can hand the frontend a NEW resource; the

MobileGL/MG_Backend/DirectGLES/Managers.h

@@ -721,7 +721,14 @@ namespace MobileGL::MG_Backend::DirectGLES {
         // asks the applier the same five questions IsBufferDrawClean asks the frontend object,
         // with identical semantics (D-A4); EnsureBufferResourceForHandle is the ensure path
         // driven by the applier's descriptor and the shadow base the call carried.
-        Bool IsBufferDrawCleanByHandle(MG_Pipe::MGPipeHandle res, const GLESBufferResource* resource);
+        //
+        // `frontend` supplies the ONE question the applier's record cannot answer in P3a: an
+        // emulated (non-adopted) persistent map is written through its pointer with no call, so
+        // MGPipeResourceRecord::HasLiveHostWrites - the field that will carry it - is pinned
+        // false and the probe still has to ask the object. It retires with P5. See the long note
+        // at the definition; passing null means "no live map", not "unknown".
+        Bool IsBufferDrawCleanByHandle(MG_Pipe::MGPipeHandle res, const GLESBufferResource* resource,
+                                       const MG_State::GLState::BufferObject* frontend);
         GLESBufferResource* EnsureBufferResourceForHandle(
             const SharedPtr<MG_State::GLState::BufferObject>& bufferObject, MG_Pipe::MGPipeHandle res);