read-cache: refactor read_index_from()

It looks better and is simpler to review when we don't compute
the same things many times in the function.

It will also help make the following commit simpler.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/read-cache.c b/read-cache.c
index 39002bc1b13ac298b76750fc00e533305f869cdd..ace3fc515b8c85c751e003b4ae66a86468cc6fdc 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -1699,6 +1699,8 @@ int read_index_from(struct index_state *istate, const char *path)
 {
        struct split_index *split_index;
        int ret;
+       char *base_sha1_hex;
+       const char *base_path;
 
        /* istate->initialized covers both .git/index and .git/sharedindex.xxx */
        if (istate->initialized)
@@ -1716,15 +1718,15 @@ int read_index_from(struct index_state *istate, const char *path)
                discard_index(split_index->base);
        else
                split_index->base = xcalloc(1, sizeof(*split_index->base));
-       ret = do_read_index(split_index->base,
-                           git_path("sharedindex.%s",
-                                    sha1_to_hex(split_index->base_sha1)), 1);
+
+       base_sha1_hex = sha1_to_hex(split_index->base_sha1);
+       base_path = git_path("sharedindex.%s", base_sha1_hex);
+       ret = do_read_index(split_index->base, base_path, 1);
        if (hashcmp(split_index->base_sha1, split_index->base->sha1))
                die("broken index, expect %s in %s, got %s",
-                   sha1_to_hex(split_index->base_sha1),
-                   git_path("sharedindex.%s",
-                            sha1_to_hex(split_index->base_sha1)),
+                   base_sha1_hex, base_path,
                    sha1_to_hex(split_index->base->sha1));
+
        merge_base_index(istate);
        post_read_index_from(istate);
        return ret;