2 files changed, 19 insertions, 4 deletions
diff --git a/src/render/renderers/opengl/renderstates/renderstateset.cpp b/src/render/renderers/opengl/renderstates/renderstateset.cpp
index b14695c77..d667d9c76 100644
--- a/src/render/renderers/opengl/renderstates/renderstateset.cpp
+++ b/src/render/renderers/opengl/renderstates/renderstateset.cpp
@@ -112,17 +112,28 @@ void RenderStateSet::merge(RenderStateSet *other)
 
     // We only add states which are new (different type)
     for (const StateVariant &otherState : otherStates) {
-        const bool hasFoundStateOfSameType = hasStateOfType(otherState.type);
-        if (!hasFoundStateOfSameType)
+        const bool canAdd = canAddStateOfType(otherState.type);
+        if (canAdd)
             m_states.push_back(otherState);
     }
 }
 
+bool RenderStateSet::canAddStateOfType(StateMask type) const
+{
+    return !hasStateOfType(type) || allowMultipleStatesOfType(type);
+}
+
 bool RenderStateSet::hasStateOfType(StateMask type) const
 {
     return (type & stateMask());
 }
 
+bool RenderStateSet::allowMultipleStatesOfType(StateMask type) const
+{
+    return (type == BlendEquationArgumentsMask) ||
+           (type == ClipPlaneMask);
+}
+
 bool RenderStateSet::contains(const StateVariant &ds) const
 {
     // trivial reject using the state mask bits
diff --git a/src/render/renderers/opengl/renderstates/renderstateset_p.h b/src/render/renderers/opengl/renderstates/renderstateset_p.h
index 29be4d2f1..c2f3a0219 100644
--- a/src/render/renderers/opengl/renderstates/renderstateset_p.h
+++ b/src/render/renderers/opengl/renderstates/renderstateset_p.h
@@ -93,8 +93,7 @@ public:
 
     QVector<StateVariant> states() const { return m_states; }
 
-    bool hasStateOfType(StateMask type) const;
-
+    bool canAddStateOfType(StateMask type) const;
 
     /**
      * @brief contains - check if this set contains a matching piece of state
@@ -102,6 +101,11 @@ public:
      * @return
      */
     bool contains(const StateVariant &ds) const;
+
+private:
+    bool hasStateOfType(StateMask type) const;
+    bool allowMultipleStatesOfType(StateMask type) const;
+
 private:
     StateMaskSet m_stateMask;
     QVector<StateVariant> m_states;