From 222a2b19a1d8eb25a1dbc3ff52873ee5274d972b Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@pobox.com>
Date: Thu, 10 Jun 2010 13:44:37 +0200
Subject: [PATCH] fix error handling when reading debugger args

* module/system/vm/debug.scm (debugger-repl): Errors reading debugger
  args no longer drop us out of the debugger.
---
 module/system/vm/debug.scm | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/module/system/vm/debug.scm b/module/system/vm/debug.scm
index be6d0312d..815135647 100644
--- a/module/system/vm/debug.scm
+++ b/module/system/vm/debug.scm
@@ -397,11 +397,16 @@ With an argument, select a frame by index, then show it."
       (catch 'quit
         (lambda ()
           (let loop ()
-            (let ((args (save-module-excursion
+            (let ((args (call-with-error-handling
                          (lambda ()
-                           (set-current-module commands)
-                           (read-args prompt)))))
-              (apply handle args)
+                           (save-module-excursion
+                            (lambda ()
+                              (set-current-module commands)
+                              (read-args prompt))))
+                         #:on-error 'pass)))
+              ;; args will be unspecified if there was a read error.
+              (if (not (unspecified? args))
+                  (apply handle args))
               (loop))))
         (lambda (k . args)
           (apply values args))))))