Merge branch 'dl/merge-autostash'

"git merge" learns the "--autostash" option.

* dl/merge-autostash: (22 commits)
  pull: pass --autostash to merge
  t5520: make test_pull_autostash() accept expect_parent_num
  merge: teach --autostash option
  sequencer: implement apply_autostash_oid()
  sequencer: implement save_autostash()
  sequencer: unlink autostash in apply_autostash()
  sequencer: extract perform_autostash() from rebase
  rebase: generify create_autostash()
  rebase: extract create_autostash()
  reset: extract reset_head() from rebase
  rebase: generify reset_head()
  rebase: use apply_autostash() from sequencer.c
  sequencer: rename stash_sha1 to stash_oid
  sequencer: make apply_autostash() accept a path
  rebase: use read_oneliner()
  sequencer: make read_oneliner() extern
  sequencer: configurably warn on non-existent files
  sequencer: make read_oneliner() accept flags
  sequencer: make file exists check more efficient
  sequencer: stop leaking buf
  ...

1 files changed, 141 insertions, 0 deletions

diff --git a/reset.c b/reset.c
new file mode 100644
index 0000000..2f4fbd0
--- /dev/null
+++ b/reset.c
@@ -0,0 +1,141 @@
+#include "git-compat-util.h"
+#include "cache-tree.h"
+#include "lockfile.h"
+#include "refs.h"
+#include "reset.h"
+#include "run-command.h"
+#include "tree-walk.h"
+#include "tree.h"
+#include "unpack-trees.h"
+
+int reset_head(struct repository *r, struct object_id *oid, const char *action,
+	       const char *switch_to_branch, unsigned flags,
+	       const char *reflog_orig_head, const char *reflog_head,
+	       const char *default_reflog_action)
+{
+	unsigned detach_head = flags & RESET_HEAD_DETACH;
+	unsigned reset_hard = flags & RESET_HEAD_HARD;
+	unsigned run_hook = flags & RESET_HEAD_RUN_POST_CHECKOUT_HOOK;
+	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;
+	struct unpack_trees_options unpack_tree_opts;
+	struct tree *tree;
+	const char *reflog_action;
+	struct strbuf msg = STRBUF_INIT;
+	size_t prefix_len;
+	struct object_id *orig = NULL, oid_orig,
+		*old_orig = NULL, oid_old_orig;
+	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);
+
+	if (!refs_only && repo_hold_locked_index(r, &lock, LOCK_REPORT_ON_ERROR) < 0) {
+		ret = -1;
+		goto leave_reset_head;
+	}
+
+	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;
+
+	if (refs_only)
+		goto reset_head_refs;
+
+	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 = r->index;
+	unpack_tree_opts.dst_index = r->index;
+	unpack_tree_opts.fn = reset_hard ? oneway_merge : twoway_merge;
+	unpack_tree_opts.update = 1;
+	unpack_tree_opts.merge = 1;
+	init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
+	if (!detach_head)
+		unpack_tree_opts.reset = 1;
+
+	if (repo_read_index_unmerged(r) < 0) {
+		ret = error(_("could not read index"));
+		goto leave_reset_head;
+	}
+
+	if (!reset_hard && !fill_tree_descriptor(r, &desc[nr++], &head_oid)) {
+		ret = error(_("failed to find tree of %s"),
+			    oid_to_hex(&head_oid));
+		goto leave_reset_head;
+	}
+
+	if (!fill_tree_descriptor(r, &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;
+	}
+
+	tree = parse_tree_indirect(oid);
+	prime_cache_tree(r, r->index, tree);
+
+	if (write_locked_index(r->index, &lock, COMMIT_LOCK) < 0) {
+		ret = error(_("could not write index"));
+		goto leave_reset_head;
+	}
+
+reset_head_refs:
+	reflog_action = getenv(GIT_REFLOG_ACTION_ENVIRONMENT);
+	strbuf_addf(&msg, "%s: ", reflog_action ? reflog_action : default_reflog_action);
+	prefix_len = msg.len;
+
+	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");
+		reflog_head = msg.buf;
+	}
+	if (!switch_to_branch)
+		ret = update_ref(reflog_head, "HEAD", oid, orig,
+				 detach_head ? REF_NO_DEREF : 0,
+				 UPDATE_REFS_MSG_ON_ERR);
+	else {
+		ret = update_ref(reflog_head, switch_to_branch, oid,
+				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
+		if (!ret)
+			ret = create_symref("HEAD", switch_to_branch,
+					    reflog_head);
+	}
+	if (run_hook)
+		run_hook_le(NULL, "post-checkout",
+			    oid_to_hex(orig ? orig : &null_oid),
+			    oid_to_hex(oid), "1", NULL);
+
+leave_reset_head:
+	strbuf_release(&msg);
+	rollback_lock_file(&lock);
+	while (nr)
+		free((void *)desc[--nr].buffer);
+	return ret;
+
+}