Be more resilient towards errors during error handling

* src/print.c (print_error_message): Avoid infinite recursion if
`substitute-command-keys' bugs out (bug#55269).

(cherry picked from commit 8364f058b821eba31f84dcded175cca403a965a5)

1 files changed, 8 insertions, 1 deletions

diff --git a/src/print.c b/src/print.c
index 3a26e5665e5..43ec0934ba1 100644
--- a/src/print.c
+++ b/src/print.c
@@ -944,7 +944,14 @@ print_error_message (Lisp_Object data, Lisp_Object stream, const char *context,
       errmsg = Fget (errname, Qerror_message);
       /* During loadup 'substitute-command-keys' might not be available.  */
       if (!NILP (Ffboundp (Qsubstitute_command_keys)))
-        errmsg = call1 (Qsubstitute_command_keys, errmsg);
+        {
+          /* `substitute-command-keys' may bug out, which would lead
+             to infinite recursion when we're called from
+             skip_debugger, so ignore errors.  */
+          Lisp_Object subs = safe_call1 (Qsubstitute_command_keys, errmsg);
+          if (!NILP (subs))
+            errmsg = subs;
+        }
 
       file_error = Fmemq (Qfile_error, error_conditions);
     }