Validate that transform feedback buffers are not mapped.

src/libANGLE/validationES.cpp

@@ -3936,7 +3936,8 @@ bool ValidateMapBufferRangeBase(Context *context,
             << "The explicit flushing bit may only be set if the buffer is mapped for writing.");
         return false;
     }
-    return true;
+
+    return ValidateMapBufferBase(context, target);
 }
 
 bool ValidateFlushMappedBufferRangeBase(Context *context,

src/libANGLE/validationES2.cpp

@@ -2777,7 +2777,7 @@ bool ValidateMapBufferOES(Context *context, GLenum target, GLenum access)
         return false;
     }
 
-    return true;
+    return ValidateMapBufferBase(context, target);
 }
 
 bool ValidateUnmapBufferOES(Context *context, GLenum target)
@@ -2806,6 +2806,30 @@ bool ValidateMapBufferRangeEXT(Context *context,
     return ValidateMapBufferRangeBase(context, target, offset, length, access);
 }
 
+bool ValidateMapBufferBase(Context *context, GLenum target)
+{
+    Buffer *buffer = context->getGLState().getTargetBuffer(target);
+    ASSERT(buffer != nullptr);
+
+    // Check if this buffer is currently being used as a transform feedback output buffer
+    TransformFeedback *transformFeedback = context->getGLState().getCurrentTransformFeedback();
+    if (transformFeedback != nullptr && transformFeedback->isActive())
+    {
+        for (size_t i = 0; i < transformFeedback->getIndexedBufferCount(); i++)
+        {
+            const auto &transformFeedbackBuffer = transformFeedback->getIndexedBuffer(i);
+            if (transformFeedbackBuffer.get() == buffer)
+            {
+                context->handleError(InvalidOperation()
+                                     << "Buffer is currently bound for transform feedback.");
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
 bool ValidateFlushMappedBufferRangeEXT(Context *context,
                                        GLenum target,
                                        GLintptr offset,

src/libANGLE/validationES2.h

@@ -208,6 +208,7 @@ bool ValidateMapBufferRangeEXT(Context *context,
                                GLintptr offset,
                                GLsizeiptr length,
                                GLbitfield access);
+bool ValidateMapBufferBase(Context *context, GLenum target);
 bool ValidateFlushMappedBufferRangeEXT(Context *context,
                                        GLenum target,
                                        GLintptr offset,

src/libANGLE/validationES3.cpp

@@ -2089,6 +2089,17 @@ bool ValidateBeginTransformFeedback(Context *context, GLenum primitiveMode)
         context->handleError(InvalidOperation() << "Transform feedback is already active.");
         return false;
     }
+
+    for (size_t i = 0; i < transformFeedback->getIndexedBufferCount(); i++)
+    {
+        const auto &buffer = transformFeedback->getIndexedBuffer(i);
+        if (buffer.get() && buffer->isMapped())
+        {
+            context->handleError(InvalidOperation() << "Transform feedback has a mapped buffer.");
+            return false;
+        }
+    }
+
     return true;
 }