builtin/merge: make checkout_fast_forward() non static
[gitweb.git] / builtin-checkout.c
index bdef1aa38699e6c74ca30b313406ef093890e902..acefaaf41a4e26e45225f6d228734c93c8f2b23c 100644 (file)
@@ -128,24 +128,6 @@ static int checkout_stage(int stage, struct cache_entry *ce, int pos,
                     (stage == 2) ? "our" : "their");
 }
 
-/* NEEDSWORK: share with merge-recursive */
-static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
-{
-       unsigned long size;
-       enum object_type type;
-
-       if (!hashcmp(sha1, null_sha1)) {
-               mm->ptr = xstrdup("");
-               mm->size = 0;
-               return;
-       }
-
-       mm->ptr = read_sha1_file(sha1, &type, &size);
-       if (!mm->ptr || type != OBJ_BLOB)
-               die("unable to read blob object %s", sha1_to_hex(sha1));
-       mm->size = size;
-}
-
 static int checkout_merged(int pos, struct checkout *state)
 {
        struct cache_entry *ce = active_cache[pos];
@@ -163,12 +145,12 @@ static int checkout_merged(int pos, struct checkout *state)
            ce_stage(active_cache[pos+2]) != 3)
                return error("path '%s' does not have all 3 versions", path);
 
-       fill_mm(active_cache[pos]->sha1, &ancestor);
-       fill_mm(active_cache[pos+1]->sha1, &ours);
-       fill_mm(active_cache[pos+2]->sha1, &theirs);
+       read_mmblob(&ancestor, active_cache[pos]->sha1);
+       read_mmblob(&ours, active_cache[pos+1]->sha1);
+       read_mmblob(&theirs, active_cache[pos+2]->sha1);
 
        status = ll_merge(&result_buf, path, &ancestor,
-                         &ours, "ours", &theirs, "theirs", 1);
+                         &ours, "ours", &theirs, "theirs", 0);
        free(ancestor.ptr);
        free(ours.ptr);
        free(theirs.ptr);
@@ -403,7 +385,7 @@ static int merge_working_tree(struct checkout_opts *opts,
                topts.initial_checkout = is_cache_unborn();
                topts.update = 1;
                topts.merge = 1;
-               topts.gently = opts->merge;
+               topts.gently = opts->merge && old->commit;
                topts.verbose_update = !opts->quiet;
                topts.fn = twoway_merge;
                topts.dir = xcalloc(1, sizeof(*topts.dir));
@@ -428,7 +410,13 @@ static int merge_working_tree(struct checkout_opts *opts,
                        struct merge_options o;
                        if (!opts->merge)
                                return 1;
-                       parse_commit(old->commit);
+
+                       /*
+                        * Without old->commit, the below is the same as
+                        * the two-tree unpack we already tried and failed.
+                        */
+                       if (!old->commit)
+                               return 1;
 
                        /* Do more real merge */
 
@@ -482,6 +470,20 @@ static void report_tracking(struct branch_info *new)
        strbuf_release(&sb);
 }
 
+static void detach_advice(const char *old_path, const char *new_name)
+{
+       const char fmt[] =
+       "Note: checking out '%s'.\n\n"
+       "You are in 'detached HEAD' state. You can look around, make experimental\n"
+       "changes and commit them, and you can discard any commits you make in this\n"
+       "state without impacting any branches by performing another checkout.\n\n"
+       "If you want to create a new branch to retain commits you create, you may\n"
+       "do so (now or later) by using -b with the checkout command again. Example:\n\n"
+       "  git checkout -b new_branch_name\n\n";
+
+       fprintf(stderr, fmt, new_name);
+}
+
 static void update_refs_for_switch(struct checkout_opts *opts,
                                   struct branch_info *old,
                                   struct branch_info *new)
@@ -516,8 +518,8 @@ static void update_refs_for_switch(struct checkout_opts *opts,
                update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
                           REF_NODEREF, DIE_ON_ERR);
                if (!opts->quiet) {
-                       if (old->path)
-                               fprintf(stderr, "Note: moving to '%s' which isn't a local branch\nIf you want to create a new branch from this checkout, you may do so\n(now or later) by using -b with the checkout command again. Example:\n  git checkout -b <new_branch_name>\n", new->name);
+                       if (old->path && advice_detached_head)
+                               detach_advice(old->path, new->name);
                        describe_detached_head("HEAD is now at", new->commit);
                }
        }
@@ -696,7 +698,10 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
         * case 3: git checkout <something> [<paths>]
         *
         *   With no paths, if <something> is a commit, that is to
-        *   switch to the branch or detach HEAD at it.
+        *   switch to the branch or detach HEAD at it.  As a special case,
+        *   if <something> is A...B (missing A or B means HEAD but you can
+        *   omit at most one side), and if there is a unique merge base
+        *   between A and B, A...B names that merge base.
         *
         *   With no paths, if <something> is _not_ a commit, no -t nor -b
         *   was given, and there is a tracking branch whose name is
@@ -722,7 +727,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                if (!strcmp(arg, "-"))
                        arg = "@{-1}";
 
-               if (get_sha1(arg, rev)) {
+               if (get_sha1_mb(arg, rev)) {
                        if (has_dash_dash)          /* case (1) */
                                die("invalid reference: %s", arg);
                        if (!patch_mode &&
@@ -749,8 +754,10 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
                new.name = arg;
                if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
                        setup_branch_path(&new);
-                       if (resolve_ref(new.path, rev, 1, NULL))
-                               new.commit = lookup_commit_reference(rev);
+
+                       if ((check_ref_format(new.path) == CHECK_REF_FORMAT_OK) &&
+                           resolve_ref(new.path, rev, 1, NULL))
+                               ;
                        else
                                new.path = NULL;
                        parse_commit(new.commit);