Fix revision log diff setup, avoid unnecessary diff generation

diff --git a/builtin-update-index.c b/builtin-update-index.c
index 8f9899178b1755ee0acd4a34ee185a4f54fb4219..a7a4574f2bff2a7db4a1c25aa4a514ad99760381 100644 (file)
--- a/builtin-update-index.c
+++ b/builtin-update-index.c
@@ -86,9 +86,15 @@ static int process_lstat_error(const char *path, int err)
 
 static int add_one_path(struct cache_entry *old, const char *path, int len, struct stat *st)
 {
-       int option, size = cache_entry_size(len);
-       struct cache_entry *ce = xcalloc(1, size);
+       int option, size;
+       struct cache_entry *ce;
+
+       /* Was the old index entry already up-to-date? */
+       if (old && !ce_stage(old) && !ce_match_stat(old, st, 0))
+               return 0;
 
+       size = cache_entry_size(len);
+       ce = xcalloc(1, size);
        memcpy(ce->name, path, len);
        ce->ce_flags = htons(len);
        fill_stat_cache_info(ce, st);
@@ -134,7 +140,7 @@ static int process_directory(const char *path, int len, struct stat *st)
        /* Exact match: file or existing gitlink */
        if (pos >= 0) {
                struct cache_entry *ce = active_cache[pos];
-               if (S_ISDIRLNK(ntohl(ce->ce_mode))) {
+               if (S_ISGITLINK(ntohl(ce->ce_mode))) {
 
                        /* Do nothing to the index if there is no HEAD! */
                        if (resolve_gitlink_ref(path, "HEAD", sha1) < 0)
@@ -178,7 +184,7 @@ static int process_file(const char *path, int len, struct stat *st)
        int pos = cache_name_pos(path, len);
        struct cache_entry *ce = pos < 0 ? NULL : active_cache[pos];
 
-       if (ce && S_ISDIRLNK(ntohl(ce->ce_mode)))
+       if (ce && S_ISGITLINK(ntohl(ce->ce_mode)))
                return error("%s is already a gitlink, not replacing", path);
 
        return add_one_path(ce, path, len, st);