Fix init-db shared database case

[git.git] / read-tree.c

diff --git a/read-tree.c b/read-tree.c
index c4ca86f..46747b5 100644 (file)
--- a/read-tree.c
+++ b/read-tree.c
@@ -15,7 +15,7 @@ static int read_one_entry(unsigned char *sha1, const char *base, int baselen, co
 
        memset(ce, 0, size);
 
-       ce->ce_mode = htonl(mode);
+       ce->ce_mode = create_ce_mode(mode);
        ce->ce_flags = create_ce_flags(baselen + len, stage);
        memcpy(ce->name, base, baselen);
        memcpy(ce->name + baselen, pathname, len+1);
@@ -73,6 +73,13 @@ static void remove_lock_file(void)
                unlink(".git/index.lock");
 }
 
+static int path_matches(struct cache_entry *a, struct cache_entry *b)
+{
+       int len = ce_namelen(a);
+       return ce_namelen(b) == len &&
+               !memcmp(a->name, b->name, len);
+}
+
 static int same(struct cache_entry *a, struct cache_entry *b)
 {
        return a->ce_mode == b->ce_mode && 
@@ -132,29 +139,73 @@ static struct cache_entry *merge_entries(struct cache_entry *a,
 
 static void trivially_merge_cache(struct cache_entry **src, int nr)
 {
+       static struct cache_entry null_entry;
        struct cache_entry **dst = src;
+       struct cache_entry *old = &null_entry;
 
        while (nr) {
                struct cache_entry *ce, *result;
 
                ce = src[0];
+
+               /* We throw away original cache entries except for the stat information */
+               if (!ce_stage(ce)) {
+                       old = ce;
+                       src++;
+                       nr--;
+                       active_nr--;
+                       continue;
+               }
                if (nr > 2 && (result = merge_entries(ce, src[1], src[2])) != NULL) {
+                       /*
+                        * See if we can re-use the old CE directly?
+                        * That way we get the uptodate stat info.
+                        */
+                       if (path_matches(result, old) && same(result, old))
+                               *result = *old;
                        ce = result;
                        ce->ce_flags &= ~htons(CE_STAGEMASK);
                        src += 2;
                        nr -= 2;
                        active_nr -= 2;
                }
-               *dst = ce;
+               *dst++ = ce;
+               src++;
+               nr--;
+       }
+}
+
+static void merge_stat_info(struct cache_entry **src, int nr)
+{
+       static struct cache_entry null_entry;
+       struct cache_entry **dst = src;
+       struct cache_entry *old = &null_entry;
+
+       while (nr) {
+               struct cache_entry *ce;
+
+               ce = src[0];
+
+               /* We throw away original cache entries except for the stat information */
+               if (!ce_stage(ce)) {
+                       old = ce;
+                       src++;
+                       nr--;
+                       active_nr--;
+                       continue;
+               }
+               if (path_matches(ce, old) && same(ce, old))
+                       *ce = *old;
+               ce->ce_flags &= ~htons(CE_STAGEMASK);
+               *dst++ = ce;
                src++;
-               dst++;
                nr--;
        }
 }
 
 int main(int argc, char **argv)
 {
-       int i, newfd;
+       int i, newfd, merge;
        unsigned char sha1[20];
 
        newfd = open(".git/index.lock", O_RDWR | O_CREAT | O_EXCL, 0600);
@@ -163,12 +214,22 @@ int main(int argc, char **argv)
        atexit(remove_lock_file);
        remove_lock = 1;
 
+       merge = 0;
        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
 
                /* "-m" stands for "merge", meaning we start in stage 1 */
                if (!strcmp(arg, "-m")) {
+                       int i;
+                       if (stage)
+                               usage("-m needs to come first");
+                       read_cache();
+                       for (i = 0; i < active_nr; i++) {
+                               if (ce_stage(active_cache[i]))
+                                       usage("you need to resolve your current index first");
+                       }
                        stage = 1;
+                       merge = 1;
                        continue;
                }
                if (get_sha1_hex(arg, sha1) < 0)
@@ -179,8 +240,18 @@ int main(int argc, char **argv)
                        die("failed to unpack tree object %s", arg);
                stage++;
        }
-       if (stage == 4)
-               trivially_merge_cache(active_cache, active_nr);
+       if (merge) {
+               switch (stage) {
+               case 4: /* Three-way merge */
+                       trivially_merge_cache(active_cache, active_nr);
+                       break;
+               case 2: /* Just read a tree, merge with old cache contents */
+                       merge_stat_info(active_cache, active_nr);
+                       break;
+               default:
+                       die("just how do you expect me to merge %d trees?", stage-1);
+               }
+       }
        if (write_cache(newfd, active_cache, active_nr) ||
            rename(".git/index.lock", ".git/index"))
                die("unable to write new index file");