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."

src/osg/Shader.cpp

@@ -240,6 +240,12 @@ void Shader::attachShader(unsigned int contextID, GLuint program) const
     if( pcs ) pcs->attachShader( program );
 }
 
+void Shader::detachShader(unsigned int contextID, GLuint program) const
+{
+    PerContextShader* pcs = getPCS( contextID );
+    if( pcs ) pcs->detachShader( program );
+}
+
 
 bool Shader::getGlShaderInfoLog(unsigned int contextID, std::string& log) const
 {