From 5ed399ca4864218dfc62d4bf614d764cf3235bfb Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 22 Oct 2013 11:18:28 +0000
Subject: [PATCH] Fixed handling of osg::Program so that it's not overriden by
 shader composition when enabled

---
 src/osg/State.cpp | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/osg/State.cpp b/src/osg/State.cpp
index 2d0db35be..62d8c7e2c 100644
--- a/src/osg/State.cpp
+++ b/src/osg/State.cpp
@@ -535,12 +535,18 @@ void State::apply(const StateSet* dstate)
             else if (unit<_textureAttributeMapList.size()) applyAttributeMapOnTexUnit(unit,_textureAttributeMapList[unit]);
         }
 
+        const Program::PerContextProgram* previousLastAppliedProgramObject = _lastAppliedProgramObject;
+
         applyModeList(_modeMap,dstate->getModeList());
         applyAttributeList(_attributeMap,dstate->getAttributeList());
 
         if (_shaderCompositionEnabled)
         {
-            applyShaderComposition();
+            if (previousLastAppliedProgramObject == _lastAppliedProgramObject || _lastAppliedProgramObject==0)
+            {
+                // No program has been applied by the StateSet stack so assume shader composition is required
+                applyShaderComposition();
+            }
         }
 
         if (dstate->getUniformList().empty())