# HG changeset patch
# User wenzelm
# Date 1220434035 -7200
# Node ID 48b9c8756020d6839afa720fe59bc9eff111af8e
# Parent  44054657ea5607f6d954088f8e5b772be020664d
theorem dependency hook: check previous state;

diff -r 44054657ea56 -r 48b9c8756020 src/Pure/ProofGeneral/proof_general_emacs.ML
--- a/src/Pure/ProofGeneral/proof_general_emacs.ML	Wed Sep 03 11:26:59 2008 +0200
+++ b/src/Pure/ProofGeneral/proof_general_emacs.ML	Wed Sep 03 11:27:15 2008 +0200
@@ -176,7 +176,9 @@
 in
 
 fun setup_present_hook () = Toplevel.add_hook (fn _ => fn state => fn state' =>
-  if print_mode_active thm_depsN andalso Toplevel.is_theory state' then
+  if print_mode_active thm_depsN andalso
+    can Toplevel.theory_of state andalso Toplevel.is_theory state'
+  then
     let val (names, deps) =
       ProofGeneralPgip.new_thms_deps (Toplevel.theory_of state) (Toplevel.theory_of state')
     in