maint: prohibit direct use of strncmp: prefer STREQ_LEN, STRNCMP_LIT

* cfg.mk (sc_prohibit_strncmp): New rule, mostly from libvirt.
* src/system.h (STREQ_LEN, STRPREFIX, STRNCMP_LIT): Define.
* src/df.c (get_dev, get_point): Convert.
* src/extent-scan.c (extent_need_sync): Likewise.
* src/ls.c (is_colored, decode_switches): Likewise.
(parse_ls_color, (print_color_indicator): Likewise.
* src/md5sum.c (split_3): Likewise.
* src/split.c (main, emit_ancillary_info): Likewise.
* src/tr.c (look_up_char_class): Likewise.
* src/uname.c (main): Likewise.
* src/who.c (scan_entries): Likewise.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/df.c b/src/df.c
index 357dca547..14f07905d 100644
--- a/src/df.c
+++ b/src/df.c
@@ -611,9 +611,9 @@ get_dev (char const *disk, char const *mount_point,
               /* Don't print the first directory name in MOUNT_POINT if it's an
                  artifact of an automounter.  This is a bit too aggressive to be
                  the default.  */
-              if (strncmp ("/auto/", mount_point, 6) == 0)
+              if (STRNCMP_LIT (mount_point, "/auto/") == 0)
                 mount_point += 5;
-              else if (strncmp ("/tmp_mnt/", mount_point, 9) == 0)
+              else if (STRNCMP_LIT (mount_point, "/tmp_mnt/") == 0)
                 mount_point += 8;
 #endif
               cell = xstrdup (mount_point);
@@ -682,7 +682,7 @@ get_point (const char *point, const struct stat *statp)
           if (best_match_len <= len && len <= resolved_len
               && (len == 1 /* root file system */
                   || ((len == resolved_len || resolved[len] == '/')
-                      && strncmp (me->me_mountdir, resolved, len) == 0)))
+                      && STREQ_LEN (me->me_mountdir, resolved, len))))
             {
               best_match = me;
               best_match_len = len;