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, 7 insertions, 5 deletions

diff --git a/ui-ssdiff.c b/ui-ssdiff.c
index 7f261ed..68c2044 100644
--- a/ui-ssdiff.c
+++ b/ui-ssdiff.c
@@ -114,11 +114,10 @@ static char *replace_tabs(char *line)
 {
         char *prev_buf = line;
         char *cur_buf;
-        int linelen = strlen(line);
+        size_t linelen = strlen(line);
         int n_tabs = 0;
         int i;
         char *result;
-        char *spaces = "        ";
 
         if (linelen == 0) {
                 result = xmalloc(1);
@@ -126,20 +125,23 @@ static char *replace_tabs(char *line)
                 return result;
         }
 
-        for (i = 0; i < linelen; i++)
+        for (i = 0; i < linelen; i++) {
                 if (line[i] == '\t')
                         n_tabs += 1;
+        }
         result = xmalloc(linelen + n_tabs * 8 + 1);
         result[0] = '\0';
 
-        while (1) {
+        for (;;) {
                 cur_buf = strchr(prev_buf, '\t');
                 if (!cur_buf) {
                         strcat(result, prev_buf);
                         break;
                 } else {
                         strncat(result, prev_buf, cur_buf - prev_buf);
-                        strncat(result, spaces, 8 - (strlen(result) % 8));
+                        linelen = strlen(result);
+                        memset(&result[linelen], ' ', 8 - (linelen % 8));
+                        result[linelen + 8 - (linelen % 8)] = '\0';
                 }
                 prev_buf = cur_buf + 1;
         }