stringbuilder: avoid overwriting end of buffer with nul terminator.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/ccan/stringbuilder/stringbuilder.c b/ccan/stringbuilder/stringbuilder.c
index d34de811b3542dbea10610f875f554dc4e734085..8eb4ab42fc812d32f5b0bb99c2b31e82fc0b90b2 100644 (file)
--- a/ccan/stringbuilder/stringbuilder.c
+++ b/ccan/stringbuilder/stringbuilder.c
@@ -22,7 +22,8 @@ static int stringbuilder_cpy(
        if (*str != s) {
                if (!s_len)
                        s_len = strlen(s);
-               if (s_len > *str_sz)
+               /* Include nul term! */
+               if (s_len >= *str_sz)
                        return EMSGSIZE;
                strcpy(*str, s);
        }