diagnose_invalid_index_path: use strbuf to avoid strcpy/strcat

We dynamically allocate a buffer and then strcpy and strcat
into it. This isn't buggy, but we'd prefer to avoid these
suspicious functions.

This would be a good candidate for converstion to xstrfmt,
but we need to record the length for dealing with index
entries. A strbuf handles that for us.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sha1_name.c b/sha1_name.c
index 80753b67704327b3bc87846069fc78a3a925bdeb..3242c5ea462ce246bbc1b90c4aeb2183b2bcbecb 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1293,8 +1293,7 @@ static void diagnose_invalid_index_path(int stage,
        const struct cache_entry *ce;
        int pos;
        unsigned namelen = strlen(filename);
-       unsigned fullnamelen;
-       char *fullname;
+       struct strbuf fullname = STRBUF_INIT;
 
        if (!prefix)
                prefix = "";
@@ -1314,21 +1313,19 @@ static void diagnose_invalid_index_path(int stage,
        }
 
        /* Confusion between relative and absolute filenames? */
-       fullnamelen = namelen + strlen(prefix);
-       fullname = xmalloc(fullnamelen + 1);
-       strcpy(fullname, prefix);
-       strcat(fullname, filename);
-       pos = cache_name_pos(fullname, fullnamelen);
+       strbuf_addstr(&fullname, prefix);
+       strbuf_addstr(&fullname, filename);
+       pos = cache_name_pos(fullname.buf, fullname.len);
        if (pos < 0)
                pos = -pos - 1;
        if (pos < active_nr) {
                ce = active_cache[pos];
-               if (ce_namelen(ce) == fullnamelen &&
-                   !memcmp(ce->name, fullname, fullnamelen))
+               if (ce_namelen(ce) == fullname.len &&
+                   !memcmp(ce->name, fullname.buf, fullname.len))
                        die("Path '%s' is in the index, but not '%s'.\n"
                            "Did you mean ':%d:%s' aka ':%d:./%s'?",
-                           fullname, filename,
-                           ce_stage(ce), fullname,
+                           fullname.buf, filename,
+                           ce_stage(ce), fullname.buf,
                            ce_stage(ce), filename);
        }
 
@@ -1338,7 +1335,7 @@ static void diagnose_invalid_index_path(int stage,
                die("Path '%s' does not exist (neither on disk nor in the index).",
                    filename);
 
-       free(fullname);
+       strbuf_release(&fullname);
 }