[PATCH v2 3/4] read-cache: introduce chmod_index_entry

[Thomas Gummerer <t.gummerer@gmail.com>]

As there are chmod options for both add and update-index, introduce a
new chmod_index_entry function to do the work.  Use it in update-index,
while it will be used in add in the next patch.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
---
 builtin/update-index.c |  8 +-------
 cache.h                |  2 ++
 read-cache.c           | 19 +++++++++++++++++++
 3 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/builtin/update-index.c b/builtin/update-index.c
index 85a57db..1569c81 100644
--- a/builtin/update-index.c
+++ b/builtin/update-index.c
@@ -423,20 +423,14 @@ static void chmod_path(int force_mode, const char *path)
 {
 	int pos;
 	struct cache_entry *ce;
-	unsigned int mode;
 	char flip = force_mode == 0777 ? '+' : '-';
 
 	pos = cache_name_pos(path, strlen(path));
 	if (pos < 0)
 		goto fail;
 	ce = active_cache[pos];
-	mode = ce->ce_mode;
-	if (!S_ISREG(mode))
+	if (chmod_cache_entry(ce, force_mode) < 0)
 		goto fail;
-	ce->ce_mode = create_ce_mode(force_mode);
-	cache_tree_invalidate_path(&the_index, path);
-	ce->ce_flags |= CE_UPDATE_IN_BASE;
-	active_cache_changed |= CE_ENTRY_CHANGED;
 
 	report("chmod %cx '%s'", flip, path);
 	return;
diff --git a/cache.h b/cache.h
index b780a91..44a4f76 100644
--- a/cache.h
+++ b/cache.h
@@ -369,6 +369,7 @@ extern void free_name_hash(struct index_state *istate);
 #define remove_file_from_cache(path) remove_file_from_index(&the_index, (path))
 #define add_to_cache(path, st, flags) add_to_index(&the_index, (path), (st), (flags), 0)
 #define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags), 0)
+#define chmod_cache_entry(ce, force_mode) chmod_index_entry(&the_index, (ce), (force_mode))
 #define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL)
 #define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
 #define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
@@ -584,6 +585,7 @@ extern int remove_file_from_index(struct index_state *, const char *path);
 extern int add_to_index(struct index_state *, const char *path, struct stat *, int flags, int force_mode);
 extern int add_file_to_index(struct index_state *, const char *path, int flags, int force_mode);
 extern struct cache_entry *make_cache_entry(unsigned int mode, const unsigned char *sha1, const char *path, int stage, unsigned int refresh_options);
+extern int chmod_index_entry(struct index_state *, struct cache_entry *ce, int force_mode);
 extern int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
 extern void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
 extern int index_name_is_other(const struct index_state *, const char *, int);
diff --git a/read-cache.c b/read-cache.c
index 491e52d..367be57 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -756,6 +756,25 @@ struct cache_entry *make_cache_entry(unsigned int mode,
 	return ret;
 }
 
+/*
+ * Change the mode of an index entry to force_mode, where force_mode can
+ * either be 0777 or 0666.
+ * Returns -1 if the chmod for the particular cache entry failed (if it's
+ * not a regular file), 0 otherwise.
+ */
+int chmod_index_entry(struct index_state *istate, struct cache_entry *ce,
+		       int force_mode)
+{
+	if (!S_ISREG(ce->ce_mode))
+		return -1;
+	ce->ce_mode = create_ce_mode(force_mode);
+	cache_tree_invalidate_path(istate, ce->name);
+	ce->ce_flags |= CE_UPDATE_IN_BASE;
+	istate->cache_changed |= CE_ENTRY_CHANGED;
+
+	return 0;
+}
+
 int ce_same_name(const struct cache_entry *a, const struct cache_entry *b)
 {
 	int len = ce_namelen(a);
-- 
2.10.0.304.gf2ff484