built-in rebase: set ORIG_HEAD just once, before the rebase

Technically, the scripted version set ORIG_HEAD only in two spots (which
really could have been one, because it called `git checkout $onto^0` to
start the rebase and also if it could take a shortcut, and in both cases
it called `git update-ref $orig_head`).

Practically, it *implicitly* reset ORIG_HEAD whenever `git reset --hard`
was called.

However, what we really want is that it is set exactly once, at the
beginning of the rebase.

So let's do that.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/rebase.c b/builtin/rebase.c
index aa469ec964d5c05a3dee6256d869e932d6f127ac..0f4e1ead4902c38ab534904e3e09428182528109 100644 (file)
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -369,6 +369,7 @@ static void add_var(struct strbuf *buf, const char *name, const char *value)
 #define RESET_HEAD_DETACH (1<<0)
 #define RESET_HEAD_HARD (1<<1)
 #define RESET_HEAD_REFS_ONLY (1<<2)
+#define RESET_ORIG_HEAD (1<<3)
 
 static int reset_head(struct object_id *oid, const char *action,
                      const char *switch_to_branch, unsigned flags,
@@ -377,6 +378,7 @@ static int reset_head(struct object_id *oid, const char *action,
        unsigned detach_head = flags & RESET_HEAD_DETACH;
        unsigned reset_hard = flags & RESET_HEAD_HARD;
        unsigned refs_only = flags & RESET_HEAD_REFS_ONLY;
+       unsigned update_orig_head = flags & RESET_ORIG_HEAD;
        struct object_id head_oid;
        struct tree_desc desc[2] = { { NULL }, { NULL } };
        struct lock_file lock = LOCK_INIT;
@@ -453,18 +455,21 @@ reset_head_refs:
        strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : "rebase");
        prefix_len = msg.len;
 
-       if (!get_oid("ORIG_HEAD", &oid_old_orig))
-               old_orig = &oid_old_orig;
-       if (!get_oid("HEAD", &oid_orig)) {
-               orig = &oid_orig;
-               if (!reflog_orig_head) {
-                       strbuf_addstr(&msg, "updating ORIG_HEAD");
-                       reflog_orig_head = msg.buf;
-               }
-               update_ref(reflog_orig_head, "ORIG_HEAD", orig, old_orig, 0,
-                          UPDATE_REFS_MSG_ON_ERR);
-       } else if (old_orig)
-               delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
+       if (update_orig_head) {
+               if (!get_oid("ORIG_HEAD", &oid_old_orig))
+                       old_orig = &oid_old_orig;
+               if (!get_oid("HEAD", &oid_orig)) {
+                       orig = &oid_orig;
+                       if (!reflog_orig_head) {
+                               strbuf_addstr(&msg, "updating ORIG_HEAD");
+                               reflog_orig_head = msg.buf;
+                       }
+                       update_ref(reflog_orig_head, "ORIG_HEAD", orig,
+                                  old_orig, 0, UPDATE_REFS_MSG_ON_ERR);
+               } else if (old_orig)
+                       delete_ref(NULL, "ORIG_HEAD", old_orig, 0);
+       }
+
        if (!reflog_head) {
                strbuf_setlen(&msg, prefix_len);
                strbuf_addstr(&msg, "updating HEAD");
@@ -1725,7 +1730,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix)
        strbuf_addf(&msg, "%s: checkout %s",
                    getenv(GIT_REFLOG_ACTION_ENVIRONMENT), options.onto_name);
        if (reset_head(&options.onto->object.oid, "checkout", NULL,
-                      RESET_HEAD_DETACH, NULL, msg.buf))
+                      RESET_HEAD_DETACH | RESET_ORIG_HEAD, NULL, msg.buf))
                die(_("Could not detach HEAD"));
        strbuf_release(&msg);
 

diff --git a/t/t3400-rebase.sh b/t/t3400-rebase.sh
index 7e8d5bb200e35ef46a48cae3ebd423f312022bce..460d0523be6f35e4477a010edd365c1f8fbd431c 100755 (executable)
--- a/t/t3400-rebase.sh
+++ b/t/t3400-rebase.sh
@@ -59,7 +59,7 @@ test_expect_success 'rebase against master' '
        git rebase master
 '
 
-test_expect_failure 'rebase sets ORIG_HEAD to pre-rebase state' '
+test_expect_success 'rebase sets ORIG_HEAD to pre-rebase state' '
        git checkout -b orig-head topic &&
        pre="$(git rev-parse --verify HEAD)" &&
        git rebase master &&