1 files changed, 28 insertions, 3 deletions

diff --git a/read-cache.c b/read-cache.c
index a363f312c7..865369df0e 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -380,7 +380,7 @@ static int index_name_pos_also_unmerged(struct index_state *istate,
 
 int add_file_to_index(struct index_state *istate, const char *path, int verbose)
 {
-	int size, namelen;
+	int size, namelen, pos;
 	struct stat st;
 	struct cache_entry *ce;
 
@@ -414,6 +414,15 @@ int add_file_to_index(struct index_state *istate, const char *path, int verbose)
 		ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
 	}
 
+	pos = index_name_pos(istate, ce->name, namelen);
+	if (0 <= pos &&
+	    !ce_stage(istate->cache[pos]) &&
+	    !ie_modified(istate, istate->cache[pos], &st, 1)) {
+		/* Nothing changed, really */
+		free(ce);
+		return 0;
+	}
+
 	if (index_path(ce->sha1, path, &st, 1))
 		die("unable to index file %s", path);
 	if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
@@ -656,7 +665,7 @@ static int check_file_directory_conflict(struct index_state *istate,
 	return retval + has_dir_name(istate, ce, pos, ok_to_replace);
 }
 
-int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
+static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
 {
 	int pos;
 	int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
@@ -698,6 +707,22 @@ int add_index_entry(struct index_state *istate, struct cache_entry *ce, int opti
 		pos = index_name_pos(istate, ce->name, ntohs(ce->ce_flags));
 		pos = -pos-1;
 	}
+	return pos + 1;
+}
+
+int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
+{
+	int pos;
+
+	if (option & ADD_CACHE_JUST_APPEND)
+		pos = istate->cache_nr;
+	else {
+		int ret;
+		ret = add_index_entry_with_check(istate, ce, option);
+		if (ret <= 0)
+			return ret;
+		pos = ret - 1;
+	}
 
 	/* Make sure the array is big enough .. */
 	if (istate->cache_nr == istate->cache_alloc) {
@@ -708,7 +733,7 @@ int add_index_entry(struct index_state *istate, struct cache_entry *ce, int opti
 
 	/* Add it in.. */
 	istate->cache_nr++;
-	if (istate->cache_nr > pos)
+	if (istate->cache_nr > pos + 1)
 		memmove(istate->cache + pos + 1,
 			istate->cache + pos,
 			(istate->cache_nr - pos - 1) * sizeof(ce));