2 files changed, 25 insertions, 0 deletions
diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index e4cb8cc71b6..adadf3c980b 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -121,6 +121,27 @@ _mesa_lookup_renderbuffer(struct gl_context *ctx, GLuint id)
 
 
 /**
+ * A convenience function for direct state access that throws
+ * GL_INVALID_OPERATION if the renderbuffer doesn't exist.
+ */
+struct gl_renderbuffer *
+_mesa_lookup_renderbuffer_err(struct gl_context *ctx, GLuint id,
+                              const char *func)
+{
+   struct gl_renderbuffer *rb;
+
+   rb = _mesa_lookup_renderbuffer(ctx, id);
+   if (!rb || rb == &DummyRenderbuffer) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "%s(non-existent renderbuffer %u)", func, id);
+      return NULL;
+   }
+
+   return rb;
+}
+
+
+/**
  * Helper routine for getting a gl_framebuffer.
  */
 struct gl_framebuffer *
diff --git a/src/mesa/main/fbobject.h b/src/mesa/main/fbobject.h
index 37d9535018b..6ac16fca241 100644
--- a/src/mesa/main/fbobject.h
+++ b/src/mesa/main/fbobject.h
@@ -64,6 +64,10 @@ _mesa_get_incomplete_framebuffer(void);
 extern struct gl_renderbuffer *
 _mesa_lookup_renderbuffer(struct gl_context *ctx, GLuint id);
 
+extern struct gl_renderbuffer *
+_mesa_lookup_renderbuffer_err(struct gl_context *ctx, GLuint id,
+                              const char *func);
+
 extern struct gl_framebuffer *
 _mesa_lookup_framebuffer(struct gl_context *ctx, GLuint id);