[Fix] (MG_Impl/GLImpl): unblock the non-texture sections of GL CTS per-case state reset - clamp advertised GL_MAX_UNIFORM_BUFFER_BINDINGS to the state layer indexed-binding capacity (glBindBufferBase rejected indices past it), let glBindRenderbuffer(0) unbind without recording INVALID_OPERATION (name 0 must never reach the name-table lookup), and allow writes to generic vertex attribute 0 current value (core GL has no attribute-0 restriction; gluStateReset writes vertexAttrib4f(0,...) after every case) - with these plus the default-texture work, multi-case glcts batches complete in one process instead of aborting after the first case

MobileGL/MG_Impl/GLImpl/Framebuffer/Validators.cpp

@@ -76,7 +76,13 @@ namespace MobileGL::MG_Impl::GLImpl::FramebufferImpl {
     }
 
     Bool ValidateRenderbufferName(Uint index, Bool allowZero) {
-        if (index == 0 && !allowZero) {
+        if (index == 0) {
+            // Zero is never a GenRenderbuffers name, so it must not reach the name-table lookup
+            // below: where it is allowed (glBindRenderbuffer / FramebufferRenderbuffer detach) it
+            // means "unbind", and looking it up would record a bogus INVALID_OPERATION - GL CTS's
+            // per-case state reset calls glBindRenderbuffer(GL_RENDERBUFFER, 0) after every case.
+            if (allowZero) return true;
+
             MG_State::pGLContext->RecordError(
                 ErrorCode::InvalidValue,
                 MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl/FramebufferImpl", "ValidateRenderbufferName",

MobileGL/MG_Impl/GLImpl/Getter/GL_Getter.cpp

@@ -1894,7 +1894,15 @@ namespace MobileGL::MG_Impl::GLImpl {
             *params = dynamicParameters.MaxTextureSize;
             break;
         case GL_MAX_UNIFORM_BUFFER_BINDINGS:
-            *params = std::max(dynamicParameters.MaxUniformBufferBindings, kFrontendMinUniformBufferBindings);
+            // Never advertise more indexed binding points than the state layer's fixed per-target
+            // array can store (BufferBindingPointCount): glBindBufferBase rejects indices past
+            // that capacity, and GL CTS's per-case state reset walks every advertised binding
+            // (gluStateReset), so an over-advertised value aborts whole test batches. The floor
+            // equals the GL 3.3 core minimum (36), so the clamp never under-advertises.
+            *params = static_cast<GLint>(std::min<SizeT>(
+                static_cast<SizeT>(std::max(dynamicParameters.MaxUniformBufferBindings,
+                                            kFrontendMinUniformBufferBindings)),
+                MG_State::GLState::BufferBindingPointCount));
             break;
         case GL_MAX_UNIFORM_BLOCK_SIZE:
             *params = dynamicParameters.MaxUniformBlockSize;

MobileGL/MG_Impl/GLImpl/VertexArray/GL_VertexArray.cpp

@@ -78,15 +78,12 @@ namespace MobileGL::MG_Impl::GLImpl {
         }
 
         static bool ValidateCurrentVertexAttribIndex(GLuint index, const char* funcName) {
-            if (!VertexArrayImpl::ValidateVertexAttributeIndex(index)) return false;
-            if (index == 0) {
-                MG_State::pGLContext->RecordError(
-                    ErrorCode::InvalidOperation,
-                    MakeUnique<GenericErrorInfo>("MG_Impl/GLImpl", funcName,
-                                                 "Generic vertex attribute 0 current value cannot be modified."));
-                return false;
-            }
-            return true;
+            // GL 3.3 core 2.7: VertexAttrib* sets the current value of ANY generic attribute,
+            // including index 0 - only an out-of-range index is an error (INVALID_VALUE).
+            // "Attribute 0 is immutable" was legacy immediate-mode lore; rejecting it broke GL
+            // CTS's per-case state reset, which writes vertexAttrib4f(0, 0,0,0,1) after every case.
+            (void)funcName;
+            return VertexArrayImpl::ValidateVertexAttributeIndex(index);
         }
 
         static bool TryGetVertexAttribute(GLuint index, const MG_State::GLState::VertexAttribute** outAttr) {

MobileGL/MG_Test/VertexArray/VertexArrayTest.cpp

@@ -1173,9 +1173,17 @@ TEST_F(GeneralVertexArrayTest, CurrentAttrib_PackedValidation) {
     GetVertexAttribfv(1, GL_CURRENT_VERTEX_ATTRIB, out);
     EXPECT_FLOAT_EQ(out[0], 42.0f); // unchanged by the failed call
 
-    // Attribute 0 is rejected by MobileGL policy (GL_INVALID_OPERATION).
+    // GL 3.3 core 2.7: attribute 0's current value is writable like any other generic
+    // attribute - no error. (An earlier MobileGL policy rejected index 0 with
+    // GL_INVALID_OPERATION, which broke GL CTS's per-case state reset: gluStateReset writes
+    // vertexAttrib4f(0, 0,0,0,1) for every attribute after every case.)
     VertexAttribP4ui(0, GL_UNSIGNED_INT_2_10_10_10_REV, GL_FALSE, 1u);
-    EXPECT_EQ(GetError(), GL_INVALID_OPERATION);
+    EXPECT_EQ(GetError(), GL_NO_ERROR);
+    GetVertexAttribfv(0, GL_CURRENT_VERTEX_ATTRIB, out);
+    EXPECT_EQ(GetError(), GL_NO_ERROR);
+    EXPECT_FLOAT_EQ(out[0], 1.0f); // x field of the packed word
+    VertexAttrib4f(0, 0.0f, 0.0f, 0.0f, 1.0f); // restore the initial current value
+    EXPECT_EQ(GetError(), GL_NO_ERROR);
 
     // Out-of-range index -> GL_INVALID_VALUE.
     VertexAttribP4ui(VertexArrayImpl::GetMaxVertexAttribs(), GL_UNSIGNED_INT_2_10_10_10_REV, GL_FALSE, 1u);