Don't try to relink programs created by glCreateShaderProgramv

* When creating a program with glCreateShaderProgramv it implicitly acts
  as if the shaders are detached and deleted after linking. This means
  it cannot be relinked again.
* However the only time we need to relink a program is when we are
  copying across fragdata and vertex attrib bindings in case they were
  changed from creation - but for the same reason that we can't relink
  a program to apply them, the application can't either - which means
  the data must be unchanged from creation, and so the copy is not
  needed.

renderdoc/driver/gl/gl_driver.h

@@ -303,6 +303,13 @@ private:
 
     map<GLint, GLint> locationTranslate;
 
+    // this flag indicates the program was created with glCreateShaderProgram and cannot be relinked
+    // again (because that function implicitly detaches and destroys the shader). However we only
+    // need to relink when restoring things like frag data or attrib bindings which must be relinked
+    // to apply - and since the application *also* could not have relinked them, they must be
+    // unchanged since creation. So in this case, we can skip the relink since it was impossible for
+    // the application to modify anything.
+    bool shaderProgramUnlinkable = false;
     bool linked;
     ResourceId stageShaders[6];
   };

renderdoc/driver/gl/gl_manager.cpp

@@ -1953,8 +1953,10 @@ void GLResourceManager::Apply_InitialState(GLResource live, InitialContentData i
         CopyProgramFragDataBindings(gl, initial.resource.name, live.name,
                                     &m_GL->m_Shaders[prog.stageShaders[4]].reflection);
 
-      // we need to re-link the program to apply the bindings.
-      gl.glLinkProgram(live.name);
+      // we need to re-link the program to apply the bindings, as long as it's linkable.
+      // See the comment on shaderProgramUnlinkable for more information.
+      if(!prog.shaderProgramUnlinkable)
+        gl.glLinkProgram(live.name);
     }
 
     CopyProgramUniforms(gl, initial.resource.name, live.name);

renderdoc/driver/gl/wrappers/gl_shader_funcs.cpp

@@ -456,6 +456,7 @@ bool WrappedOpenGL::Serialise_glCreateShaderProgramv(GLuint program, GLenum type
     progDetails.linked = true;
     progDetails.shaders.push_back(liveId);
     progDetails.stageShaders[ShaderIdx(Type)] = liveId;
+    progDetails.shaderProgramUnlinkable = true;
 
     auto &shadDetails = m_Shaders[liveId];