1 files changed, 4 insertions, 5 deletions
diff --git a/mrbgems/mruby-bin-debugger/tools/mrdb/cmdmisc.c b/mrbgems/mruby-bin-debugger/tools/mrdb/cmdmisc.c
index a05ff9415..0714f3f21 100644
--- a/mrbgems/mruby-bin-debugger/tools/mrdb/cmdmisc.c
+++ b/mrbgems/mruby-bin-debugger/tools/mrdb/cmdmisc.c
@@ -8,6 +8,7 @@
 #include <string.h>
 
 #include "apilist.h"
+#include "apistring.h"
 #include <mruby/compile.h>
 
 typedef struct help_msg {
@@ -140,7 +141,8 @@ static listcmd_parser_state*
 listcmd_parser_state_new(mrb_state *mrb)
 {
   listcmd_parser_state *st = (listcmd_parser_state*)mrb_malloc(mrb, sizeof(listcmd_parser_state));
-  memset(st, 0, sizeof(listcmd_parser_state));
+  static const listcmd_parser_state st_zero = {0};
+  *st = st_zero;
   return st;
 }
 
@@ -232,10 +234,7 @@ parse_filename(mrb_state *mrb, char **sp, listcmd_parser_state *st)
     len = strlen(*sp);
   }
 
-  if (len > 0) {
-    st->filename = (char*)mrb_malloc(mrb, len + 1);
-    strncpy(st->filename, *sp, len);
-    st->filename[len] = '\0';
+  if (len > 0 && (st->filename = mrdb_strndup(mrb, *sp, len)) != NULL) {
     *sp += len;
     return TRUE;
   }