diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4d5eaa8a6b..58310db150 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2010-01-01  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* cli/cli-script.c (process_next_line): Check P2 overrun.
+
 2009-01-01  Joel Brobecker  <brobecker@adacore.com>
 
 	Update the copyright hearder to add year 2010 for most GDB files.
diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 4509cfc10c..dae4d64c4d 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -893,7 +893,7 @@ process_next_line (char *p, struct command_line **command, int parse_commands)
 
   p2 = p;
   /* Strip leading whitespace.  */
-  while (*p2 == ' ' || *p2 == '\t')
+  while (p2 != p1 && (*p2 == ' ' || *p2 == '\t'))
     p2++;
 
   /* 'end' is always recognized, regardless of parse_commands value.