Fix gcc 8.1.1 compiler warnings

    CC ../shared.o
../shared.c: In function ‘expand_macro’:
../shared.c:487:3: warning: ‘strncpy’ specified bound depends on the length of the source argument [-Wstringop-overflow=]
   strncpy(name, value, len);
   ^~~~~~~~~~~~~~~~~~~~~~~~~
../shared.c:484:9: note: length computed here
   len = strlen(value);
         ^~~~~~~~~~~~~
../ui-shared.c: In function ‘cgit_repobasename’:
../ui-shared.c:136:2: warning: ‘strncpy’ specified bound 1024 equals destination size [-Wstringop-truncation]
  strncpy(rvbuf, reponame, sizeof(rvbuf));
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    CC ../ui-ssdiff.o
../ui-ssdiff.c: In function ‘replace_tabs’:
../ui-ssdiff.c:142:4: warning: ‘strncat’ output truncated copying between 1 and 8 bytes from a string of length 8 [-Wstringop-truncation]
    strncat(result, spaces, 8 - (strlen(result) % 8));
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 12 insertions, 7 deletions

diff --git a/ui-shared.c b/ui-shared.c
index 066a470..739505a 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -133,20 +133,25 @@ const char *cgit_repobasename(const char *reponame)
         static char rvbuf[1024];
         int p;
         const char *rv;
-        strncpy(rvbuf, reponame, sizeof(rvbuf));
-        if (rvbuf[sizeof(rvbuf)-1])
+        size_t len;
+
+        len = strlcpy(rvbuf, reponame, sizeof(rvbuf));
+        if (len >= sizeof(rvbuf))
                 die("cgit_repobasename: truncated repository name '%s'", reponame);
-        p = strlen(rvbuf)-1;
+        p = len - 1;
         /* strip trailing slashes */
-        while (p && rvbuf[p] == '/') rvbuf[p--] = 0;
+        while (p && rvbuf[p] == '/')
+                rvbuf[p--] = '\0';
         /* strip trailing .git */
         if (p >= 3 && starts_with(&rvbuf[p-3], ".git")) {
-                p -= 3; rvbuf[p--] = 0;
+                p -= 3;
+                rvbuf[p--] = '\0';
         }
         /* strip more trailing slashes if any */
-        while ( p && rvbuf[p] == '/') rvbuf[p--] = 0;
+        while (p && rvbuf[p] == '/')
+                rvbuf[p--] = '\0';
         /* find last slash in the remaining string */
-        rv = strrchr(rvbuf,'/');
+        rv = strrchr(rvbuf, '/');
         if (rv)
                 return ++rv;
         return rvbuf;