From bac2a1e36ffd7ae8b62e1ba708b64979c0f10ee8 Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Mon, 12 Nov 2018 03:44:32 -0800 Subject: [PATCH] built-in rebase: reinstate `checkout -q` behavior where appropriate When we converted a `git checkout -q $onto^0` call to use `reset_head()`, we inadvertently incurred a change from a twoway_merge to a oneway_merge, as if we wanted a `git reset --hard` instead. This has performance ramifications under certain, though, as the oneway_merge needs to lstat() every single index entry whereas twoway_merge does not. So let's go back to the old behavior. Signed-off-by: Johannes Schindelin Signed-off-by: Junio C Hamano --- builtin/rebase.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) diff --git a/builtin/rebase.c b/builtin/rebase.c index 074594cf10..dc78c1497d 100644 --- a/builtin/rebase.c +++ b/builtin/rebase.c @@ -523,14 +523,16 @@ finished_rebase: #define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION" #define RESET_HEAD_DETACH (1<<0) +#define RESET_HEAD_HARD (1<<1) static int reset_head(struct object_id *oid, const char *action, const char *switch_to_branch, unsigned flags, const char *reflog_orig_head, const char *reflog_head) { unsigned detach_head = flags & RESET_HEAD_DETACH; + unsigned reset_hard = flags & RESET_HEAD_HARD; struct object_id head_oid; - struct tree_desc desc; + struct tree_desc desc[2] = { { NULL }, { NULL } }; struct lock_file lock = LOCK_INIT; struct unpack_trees_options unpack_tree_opts; struct tree *tree; @@ -539,7 +541,7 @@ static int reset_head(struct object_id *oid, const char *action, size_t prefix_len; struct object_id *orig = NULL, oid_orig, *old_orig = NULL, oid_old_orig; - int ret = 0; + int ret = 0, nr = 0; if (switch_to_branch && !starts_with(switch_to_branch, "refs/")) BUG("Not a fully qualified branch: '%s'", switch_to_branch); @@ -549,20 +551,20 @@ static int reset_head(struct object_id *oid, const char *action, goto leave_reset_head; } - if (!oid) { - if (get_oid("HEAD", &head_oid)) { - ret = error(_("could not determine HEAD revision")); - goto leave_reset_head; - } - oid = &head_oid; + if ((!oid || !reset_hard) && get_oid("HEAD", &head_oid)) { + ret = error(_("could not determine HEAD revision")); + goto leave_reset_head; } + if (!oid) + oid = &head_oid; + memset(&unpack_tree_opts, 0, sizeof(unpack_tree_opts)); setup_unpack_trees_porcelain(&unpack_tree_opts, action); unpack_tree_opts.head_idx = 1; unpack_tree_opts.src_index = the_repository->index; unpack_tree_opts.dst_index = the_repository->index; - unpack_tree_opts.fn = oneway_merge; + unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge; unpack_tree_opts.update = 1; unpack_tree_opts.merge = 1; if (!detach_head) @@ -573,12 +575,17 @@ static int reset_head(struct object_id *oid, const char *action, goto leave_reset_head; } - if (!fill_tree_descriptor(&desc, oid)) { + if (!reset_hard && !fill_tree_descriptor(&desc[nr++], &head_oid)) { ret = error(_("failed to find tree of %s"), oid_to_hex(oid)); goto leave_reset_head; } - if (unpack_trees(1, &desc, &unpack_tree_opts)) { + if (!fill_tree_descriptor(&desc[nr++], oid)) { + ret = error(_("failed to find tree of %s"), oid_to_hex(oid)); + goto leave_reset_head; + } + + if (unpack_trees(nr, desc, &unpack_tree_opts)) { ret = -1; goto leave_reset_head; } @@ -625,7 +632,8 @@ static int reset_head(struct object_id *oid, const char *action, leave_reset_head: strbuf_release(&msg); rollback_lock_file(&lock); - free((void *)desc.buffer); + while (nr) + free((void *)desc[--nr].buffer); return ret; } @@ -1003,7 +1011,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix) rerere_clear(&merge_rr); string_list_clear(&merge_rr, 1); - if (reset_head(NULL, "reset", NULL, 0, NULL, NULL) < 0) + if (reset_head(NULL, "reset", NULL, RESET_HEAD_HARD, + NULL, NULL) < 0) die(_("could not discard worktree changes")); if (read_basic_state(&options)) exit(1); @@ -1019,7 +1028,8 @@ int cmd_rebase(int argc, const char **argv, const char *prefix) if (read_basic_state(&options)) exit(1); if (reset_head(&options.orig_head, "reset", - options.head_name, 0, NULL, NULL) < 0) + options.head_name, RESET_HEAD_HARD, + NULL, NULL) < 0) die(_("could not move back to %s"), oid_to_hex(&options.orig_head)); ret = finish_rebase(&options); @@ -1383,7 +1393,7 @@ int cmd_rebase(int argc, const char **argv, const char *prefix) write_file(autostash, "%s", oid_to_hex(&oid)); printf(_("Created autostash: %s\n"), buf.buf); if (reset_head(&head->object.oid, "reset --hard", - NULL, 0, NULL, NULL) < 0) + NULL, RESET_HEAD_HARD, NULL, NULL) < 0) die(_("could not reset --hard")); printf(_("HEAD is now at %s"), find_unique_abbrev(&head->object.oid,