string_utils: get around GCC-11 false positives

by getting rid of stpncpy

Tested with gcc (GCC) 11.1.1 20210428 (Red Hat 11.1.1-1)

Closes https://github.com/lxc/lxc/issues/3752

Signed-off-by: Evgeny Vereshchagin <evvers@ya.ru>

diff --git a/src/lxc/string_utils.c b/src/lxc/string_utils.c
index 366cbd9ed984a15c0a8914185d965bc2474595c9..9c54819a085551c217d581c8b0179286a247876a 100644 (file)
--- a/src/lxc/string_utils.c
+++ b/src/lxc/string_utils.c
@@ -877,14 +877,18 @@ int parse_byte_size_string(const char *s, long long int *converted)
        char *end;
        char dup[INTTYPE_TO_STRLEN(long long int)] = {0};
        char suffix[3] = {0};
+       size_t len;
 
-       if (is_empty_string(s))
+       if (!s)
                return ret_errno(EINVAL);
 
-       end = stpncpy(dup, s, sizeof(dup) - 1);
-       if (*end != '\0')
+       len = strlen(s);
+       if (len == 0 || len > sizeof(dup) - 1)
                return ret_errno(EINVAL);
 
+       memcpy(dup, s, len);
+
+       end = dup + len;
        if (isdigit(*(end - 1)))
                suffix_len = 0;
        else if (isalpha(*(end - 1)))