* src/eval.c: Add `inhibit-debugger'.

(Qinhibit_debugger): New symbol.
(call_debugger): Bind it instead of Qdebug_on_error.
(maybe_call_debugger): Test Vinhibit_debugger.
(syms_of_eval): Define inhibit-debugger.
* src/xdisp.c (set_message): Don't bind Qinhibit_debug_on_message.
(syms_of_xdisp): Remove inhibit-debug-on-message.
* lisp/emacs-lisp/debug.el (debug): Don't bind debug-on-error since
inhibit-debugger is bound instead.

5 files changed, 27 insertions, 23 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index f4cae50d8ed..a005b1d80c7 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,13 @@
+2012-09-12  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+	* eval.c: Add `inhibit-debugger'.
+	(Qinhibit_debugger): New symbol.
+	(call_debugger): Bind it instead of Qdebug_on_error.
+	(maybe_call_debugger): Test Vinhibit_debugger.
+	(syms_of_eval): Define inhibit-debugger.
+	* xdisp.c (set_message): Don't bind Qinhibit_debug_on_message.
+	(syms_of_xdisp): Remove inhibit-debug-on-message.
+
 2012-09-11  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Avoid _setjmp/_longjmp problems with local nonvolatile variables.
diff --git a/src/composite.h b/src/composite.h
index 68f5b27ee42..9462b932c66 100644
--- a/src/composite.h
+++ b/src/composite.h
@@ -113,7 +113,7 @@ extern Lisp_Object composition_temp;
    && (end - start) == COMPOSITION_LENGTH (prop))
 
 /* Return the Nth glyph of composition specified by CMP.  CMP is a
-   pointer to `struct composition'. */
+   pointer to `struct composition'.  */
 #define COMPOSITION_GLYPH(cmp, n)					\
   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)		\
 			  ->key_and_value)				\
diff --git a/src/eval.c b/src/eval.c
index 4f0d6c69a51..8a8a507a1b6 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -69,7 +69,7 @@ Lisp_Object Qautoload, Qmacro, Qexit, Qinteractive, Qcommandp;
 Lisp_Object Qinhibit_quit;
 Lisp_Object Qand_rest;
 static Lisp_Object Qand_optional;
-static Lisp_Object Qdebug_on_error;
+static Lisp_Object Qinhibit_debugger;
 static Lisp_Object Qdeclare;
 Lisp_Object Qinternal_interpreter_environment, Qclosure;
 
@@ -229,7 +229,7 @@ call_debugger (Lisp_Object arg)
   specbind (intern ("debugger-may-continue"),
 	    debug_while_redisplaying ? Qnil : Qt);
   specbind (Qinhibit_redisplay, Qnil);
-  specbind (Qdebug_on_error, Qnil);
+  specbind (Qinhibit_debugger, Qt);
 
 #if 0 /* Binding this prevents execution of Lisp code during
 	 redisplay, which necessarily leads to display problems.  */
@@ -1725,6 +1725,7 @@ maybe_call_debugger (Lisp_Object conditions, Lisp_Object sig, Lisp_Object data)
       /* Don't try to run the debugger with interrupts blocked.
 	 The editing loop would return anyway.  */
       ! INPUT_BLOCKED_P
+      && NILP (Vinhibit_debugger)
       /* Does user want to enter debugger for this kind of error?  */
       && (EQ (sig, Qquit)
 	  ? debug_on_quit
@@ -3467,7 +3468,7 @@ before making `inhibit-quit' nil.  */);
 
   DEFSYM (Qinhibit_quit, "inhibit-quit");
   DEFSYM (Qautoload, "autoload");
-  DEFSYM (Qdebug_on_error, "debug-on-error");
+  DEFSYM (Qinhibit_debugger, "inhibit-debugger");
   DEFSYM (Qmacro, "macro");
   DEFSYM (Qdeclare, "declare");
 
@@ -3482,6 +3483,12 @@ before making `inhibit-quit' nil.  */);
   DEFSYM (Qclosure, "closure");
   DEFSYM (Qdebug, "debug");
 
+  DEFVAR_LISP ("inhibit-debugger", Vinhibit_debugger,
+	       doc: /* Non-nil means never enter the debugger.
+Normally set while the debugger is already active, to avoid recursive
+invocations.  */);
+  Vinhibit_debugger = Qnil;
+
   DEFVAR_LISP ("debug-on-error", Vdebug_on_error,
 	       doc: /* Non-nil means enter debugger if an error is signaled.
 Does not apply to errors handled by `condition-case' or those
@@ -3491,7 +3498,7 @@ if one of its condition symbols appears in the list.
 When you evaluate an expression interactively, this variable
 is temporarily non-nil if `eval-expression-debug-on-error' is non-nil.
 The command `toggle-debug-on-error' toggles this.
-See also the variable `debug-on-quit'.  */);
+See also the variable `debug-on-quit' and `inhibit-debugger'.  */);
   Vdebug_on_error = Qnil;
 
   DEFVAR_LISP ("debug-ignored-errors", Vdebug_ignored_errors,
diff --git a/src/keyboard.c b/src/keyboard.c
index 42c67f68ede..8091258578c 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -4133,7 +4133,7 @@ kbd_buffer_get_event (KBOARD **kbp,
 		*used_mouse_menu = 1;
 #endif
 #ifdef HAVE_NS
-	      /* certain system events are non-key events */
+	      /* Certain system events are non-key events.  */
 	      if (used_mouse_menu
                   && event->kind == NS_NONKEY_EVENT)
 		*used_mouse_menu = 1;
@@ -4161,7 +4161,7 @@ kbd_buffer_get_event (KBOARD **kbp,
 	 so x remains nil.  */
       x = Qnil;
 
-      /* XXX Can f or mouse_position_hook be NULL here? */
+      /* XXX Can f or mouse_position_hook be NULL here?  */
       if (f && FRAME_TERMINAL (f)->mouse_position_hook)
         (*FRAME_TERMINAL (f)->mouse_position_hook) (&f, 0, &bar_window,
                                                     &part, &x, &y, &t);
diff --git a/src/xdisp.c b/src/xdisp.c
index c1e05d6df15..e9d9595d91e 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -364,7 +364,6 @@ static Lisp_Object Qslice;
 Lisp_Object Qcenter;
 static Lisp_Object Qmargin, Qpointer;
 static Lisp_Object Qline_height;
-static Lisp_Object Qinhibit_debug_on_message;
 
 /* These setters are used only in this file, so they can be private.  */
 static inline void
@@ -10590,8 +10589,6 @@ static void
 set_message (const char *s, Lisp_Object string,
 	     ptrdiff_t nbytes, int multibyte_p)
 {
-  ptrdiff_t count = SPECPDL_INDEX ();
-
   message_enable_multibyte
     = ((s && multibyte_p)
        || (STRINGP (string) && STRING_MULTIBYTE (string)));
@@ -10601,14 +10598,9 @@ set_message (const char *s, Lisp_Object string,
   message_buf_print = 0;
   help_echo_showing_p = 0;
 
-  if (NILP (Vinhibit_debug_on_message) && STRINGP (Vdebug_on_message)
+  if (STRINGP (Vdebug_on_message)
       && fast_string_match (Vdebug_on_message, string) >= 0)
-    {
-      specbind (Qinhibit_debug_on_message, Qt);
-      call_debugger (list2 (Qerror, string));
-    }
-
-  unbind_to (count, Qnil);
+    call_debugger (list2 (Qerror, string));
 }
 
 
@@ -12800,7 +12792,7 @@ overlay_arrow_at_row (struct it *it, struct glyph_row *row)
 		    return make_number (fringe_bitmap);
 		}
 #endif
-	      return make_number (-1); /* Use default arrow bitmap */
+	      return make_number (-1); /* Use default arrow bitmap.  */
 	    }
 	  return overlay_arrow_string_or_property (var);
 	}
@@ -29316,11 +29308,6 @@ Its value should be an ASCII acronym string, `hex-code', `empty-box', or
   DEFVAR_LISP ("debug-on-message", Vdebug_on_message,
 	       doc: /* If non-nil, debug if a message matching this regexp is displayed.  */);
   Vdebug_on_message = Qnil;
-
-  DEFVAR_LISP ("inhibit-debug-on-message", Vinhibit_debug_on_message,
-	       doc: /* If non-nil, inhibit `debug-on-message' from entering the debugger.  */);
-  Vinhibit_debug_on_message = Qnil;
-  DEFSYM(Qinhibit_debug_on_message, "inhibit-debug-on-message");
 }