(delete_kboard): Prevent a dangling reference

from current_kboard to KB, which is freed.

2 files changed, 19 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index bf411ea416f..16ed4171305 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,8 @@
 2001-04-19  Gerd Moellmann  <gerd@gnu.org>
 
+        * keyboard.c (delete_kboard): Prevent a dangling reference
+        from current_kboard to KB, which is freed.
+
         * process.c (wait_reading_process_input): Call
         record_asynch_buffer_change after running timers, to make
         read_key_sequence aware of buffer changes from under it.
diff --git a/src/keyboard.c b/src/keyboard.c
index 1d984be4fcc..a9dd324a381 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -10013,19 +10013,33 @@ wipe_kboard (kb)
 }
 
 #ifdef MULTI_KBOARD
+
+/* Free KB and memory referenced from it.  */
+
 void
 delete_kboard (kb)
-  KBOARD *kb;
+     KBOARD *kb;
 {
   KBOARD **kbp;
+  
   for (kbp = &all_kboards; *kbp != kb; kbp = &(*kbp)->next_kboard)
     if (*kbp == NULL)
       abort ();
   *kbp = kb->next_kboard;
+
+  /* Prevent a dangling reference to KB.  */
+  if (kb == current_kboard)
+    {
+      current_kboard = SELECTED_FRAME ()->kboard;
+      if (current_kboard == kb)
+        abort ();
+    }
+  
   wipe_kboard (kb);
   xfree (kb);
 }
-#endif
+
+#endif /* MULTI_KBOARD */
 
 void
 init_keyboard ()