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[PATCH] Fix segfault on empty else
- From: Andrew STUBBS <andrew dot stubbs at st dot com>
- To: GDB Patches <gdb-patches at sourceware dot org>
- Date: Tue, 20 Jun 2006 15:33:37 +0100
- Subject: [PATCH] Fix segfault on empty else
The attached patch fixes a segmentation fault that occurs when a GDB
script has an empty else clause.
E.g.
if $cond
echo here\n
else
# boom
end
The command structure is apparently read correctly (from the user's
perspective), but GDB will crash when it tries to a) execute the else
clause ($cond == 0), or b) free the command, if the command is not in a
define or the user-defined command is redefined.
This problem is caused by a pointer that is only initialised when it is
first used, which is never when there are no commands.
:ADDPATCH CLI:
Andrew Stubbs
2006-06-20 Andrew Stubbs <andrew.stubbs@st.com>
* cli/cli-script.c (realloc_body_list): Zero new parts of body_list.
Index: src/gdb/cli/cli-script.c
===================================================================
--- src.orig/gdb/cli/cli-script.c 2006-04-07 14:31:15.000000000 +0100
+++ src/gdb/cli/cli-script.c 2006-06-20 15:15:25.000000000 +0100
@@ -701,6 +701,7 @@ realloc_body_list (struct command_line *
xmalloc (sizeof (struct command_line *) * new_length);
memcpy (body_list, command->body_list, sizeof (struct command_line *) * n);
+ memset (body_list + n, 0, sizeof (struct command_line *) * (new_length - n));
xfree (command->body_list);
command->body_list = body_list;