fix set_attrib() with override

panda/src/pgraph/pandaNode.cxx

@@ -1055,7 +1055,7 @@ set_attrib(const RenderAttrib *attrib, int override) {
   OPEN_ITERATE_CURRENT_AND_UPSTREAM(_cycler, current_thread) {
     CDStageWriter cdata(_cycler, pipeline_stage, current_thread);
     
-    CPT(RenderState) new_state = cdata->_state->add_attrib(attrib, override);
+    CPT(RenderState) new_state = cdata->_state->set_attrib(attrib, override);
     if (cdata->_state != new_state) {
       cdata->_state = new_state;
       cdata->set_fancy_bit(FB_state, true);

panda/src/pgraph/renderState.cxx

@@ -613,6 +613,57 @@ set_attrib(const RenderAttrib *attrib) const {
   return return_new(new_state);
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: RenderState::set_attrib
+//       Access: Published
+//  Description: Returns a new RenderState object that represents the
+//               same as the source state, with the new RenderAttrib
+//               added.  If there is already a RenderAttrib with the
+//               same type, it is replaced unconditionally.  The
+//               override is also replaced unconditionally.
+////////////////////////////////////////////////////////////////////
+CPT(RenderState) RenderState::
+set_attrib(const RenderAttrib *attrib, int override) const {
+  RenderState *new_state = new RenderState;
+  back_insert_iterator<Attributes> result = 
+    back_inserter(new_state->_attributes);
+
+  Attribute new_attribute(attrib, override);
+  Attributes::const_iterator ai = _attributes.begin();
+
+  while (ai != _attributes.end() && (*ai) < new_attribute) {
+    *result = *ai;
+    ++ai;
+    ++result;
+  }
+
+  if (ai != _attributes.end() && !(new_attribute < (*ai))) {
+    // At this point we know: !((*ai) < new_attribute) &&
+    // !(new_attribute < (*ai)) which means (*ai) == new_attribute, so
+    // there is another attribute of the same type already in the
+    // state.
+
+    (*result) = Attribute(attrib, override);
+    ++ai;
+    ++result;
+
+  } else {
+    // There is not another attribute of the same type already in the
+    // state.
+    *result = new_attribute;
+    ++result;
+  }
+
+
+  while (ai != _attributes.end()) {
+    *result = *ai;
+    ++ai;
+    ++result;
+  }
+
+  return return_new(new_state);
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: RenderState::remove_attrib
 //       Access: Published

panda/src/pgraph/renderState.h

@@ -108,6 +108,7 @@ PUBLISHED:
 
   CPT(RenderState) add_attrib(const RenderAttrib *attrib, int override = 0) const;
   CPT(RenderState) set_attrib(const RenderAttrib *attrib) const;
+  CPT(RenderState) set_attrib(const RenderAttrib *attrib, int override) const;
   CPT(RenderState) remove_attrib(TypeHandle type) const;
 
   CPT(RenderState) adjust_all_priorities(int adjustment) const;