check length of extend_lowat

diff --git a/src/lib/util/sbuff.h b/src/lib/util/sbuff.h
index ed6def0746f3e5441c9e0270701b483786f9b1d7..7ce46ff349a21ecf7bfccc8e47036e97febb513f 100644 (file)
--- a/src/lib/util/sbuff.h
+++ b/src/lib/util/sbuff.h
@@ -1769,7 +1769,7 @@ static inline bool fr_sbuff_is_in_charset(fr_sbuff_t *sbuff, bool const chars[st
 static inline bool fr_sbuff_is_str(fr_sbuff_t *sbuff, char const *str, size_t len)
 {
        if (len == SIZE_MAX) len = strlen(str);
-       if (!fr_sbuff_extend_lowat(NULL, sbuff, len)) return false;
+       if (fr_sbuff_extend_lowat(NULL, sbuff, len) < len) return false;
        return memcmp(sbuff->p, str, len) == 0;
 }
 #define fr_sbuff_is_str_literal(_sbuff, _str) fr_sbuff_is_str(_sbuff, _str, sizeof(_str) - 1)