Prevent heap-buffer-overflow in Strnew_size()

Bug-Debian: https://github.com/tats/w3m/issues/72
Origin: https://anonscm.debian.org/cgit/collab-maint/w3m.git/commit/?id=4381dffaa3fdf94c384f3588b5c7dff3ba1cc4ae

1 files changed, 2 insertions, 0 deletions

diff --git a/Str.c b/Str.c
index 5287c0f..7a094f5 100644
--- a/Str.c
+++ b/Str.c
@@ -48,6 +48,8 @@ Str
 Strnew_size(int n)
 {
     Str x = GC_MALLOC(sizeof(struct _Str));
+    if (n < 0)
+	n = 0;
     x->ptr = GC_MALLOC_ATOMIC(n + 1);
     x->ptr[0] = '\0';
     x->area_size = n + 1;