From Per Fahlberg, "Attached is a fix allowing removal of shaders from a program after it is

first compiled. It will also allow new shaders to be attached after the
program is first compiled."

include/osg/Program

@@ -203,6 +203,16 @@ class OSG_EXPORT Program : public osg::StateAttribute
                 inline GLint getUniformLocation( const std::string& name ) const { ActiveVarInfoMap::const_iterator itr = _uniformInfoMap.find(name); return (itr!=_uniformInfoMap.end()) ? itr->second._location : -1; }
                 inline GLint getAttribLocation( const std::string& name ) const { ActiveVarInfoMap::const_iterator itr = _attribInfoMap.find(name); return (itr!=_attribInfoMap.end()) ? itr->second._location : -1; }
 
+                inline void addShaderToAttach(Shader *shader)
+                {
+                    _shadersToAttach.push_back(shader);
+                }
+
+                inline void addShaderToDetach(Shader *shader)
+                {
+                    _shadersToDetach.push_back(shader);
+                }
+      
             protected:        /*methods*/
                 ~PerContextProgram();
 
@@ -225,6 +235,10 @@ class OSG_EXPORT Program : public osg::StateAttribute
                 typedef std::pair<const osg::Uniform*, unsigned int> UniformModifiedCountPair;
                 typedef std::vector<UniformModifiedCountPair> LastAppliedUniformList;
                 mutable LastAppliedUniformList _lastAppliedUniformList;
+      
+                typedef std::vector< ref_ptr<Shader> > ShaderList;
+                ShaderList _shadersToDetach;
+                ShaderList _shadersToAttach;
 
             private:
                 PerContextProgram();        // disallowed
@@ -247,7 +261,6 @@ class OSG_EXPORT Program : public osg::StateAttribute
         typedef std::vector< ref_ptr<Shader> > ShaderList;
         ShaderList _shaderList;
 
-
     private:
         Program& operator=(const Program&);        // disallowed
 };

include/osg/Shader

@@ -99,6 +99,9 @@ class OSG_EXPORT Shader : public osg::Object
         /** For a given GL context, attach a glShader to a glProgram */
         void attachShader(unsigned int contextID, GLuint program) const;
 
+        /** For a given GL context, detach a glShader to a glProgram */
+        void detachShader(unsigned int contextID, GLuint program) const;
+
         /** Query InfoLog from a glShader */
         bool getGlShaderInfoLog(unsigned int contextID, std::string& log) const;