From 805d9eaf5eab0edc3567d9e19e74a3f9168e764a Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Sat, 21 Mar 2020 05:21:20 -0400
Subject: Makefile: ASCII-sort += lists

There are many += lists in the Makefile and, over time, they have gotten
slightly out of ASCII order. Sort all += lists to bring them back in
order.

ASCII sorting was chosen over strict alphabetical order even though, if
we omit file prefixes, the lists aren't sorted in strictly alphabetical
order (e.g. archive.o comes after archive-zip.o instead of before
archive-tar.o). This is intentional because the purpose of maintaining
the sorted list is to ensure line insertions are deterministic. By using
ASCII ordering, it is more easily mechanically reproducible in the
future, such as by using :sort in Vim.

This patch is best viewed with `--color-moved`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Makefile | 77 ++++++++++++++++++++++++++++++++--------------------------------
 1 file changed, 39 insertions(+), 38 deletions(-)

(limited to 'Makefile')

diff --git a/Makefile b/Makefile
index 9804a0758b..f709fc3f77 100644
--- a/Makefile
+++ b/Makefile
@@ -604,12 +604,12 @@ unexport CDPATH
 SCRIPT_SH += git-bisect.sh
 SCRIPT_SH += git-difftool--helper.sh
 SCRIPT_SH += git-filter-branch.sh
+SCRIPT_SH += git-legacy-stash.sh
 SCRIPT_SH += git-merge-octopus.sh
 SCRIPT_SH += git-merge-one-file.sh
 SCRIPT_SH += git-merge-resolve.sh
 SCRIPT_SH += git-mergetool.sh
 SCRIPT_SH += git-quiltimport.sh
-SCRIPT_SH += git-legacy-stash.sh
 SCRIPT_SH += git-request-pull.sh
 SCRIPT_SH += git-submodule.sh
 SCRIPT_SH += git-web--browse.sh
@@ -617,8 +617,8 @@ SCRIPT_SH += git-web--browse.sh
 SCRIPT_LIB += git-mergetool--lib
 SCRIPT_LIB += git-parse-remote
 SCRIPT_LIB += git-rebase--preserve-merges
-SCRIPT_LIB += git-sh-setup
 SCRIPT_LIB += git-sh-i18n
+SCRIPT_LIB += git-sh-setup
 
 SCRIPT_PERL += git-add--interactive.perl
 SCRIPT_PERL += git-archimport.perl
@@ -686,9 +686,9 @@ PROGRAM_OBJS += daemon.o
 PROGRAM_OBJS += fast-import.o
 PROGRAM_OBJS += http-backend.o
 PROGRAM_OBJS += imap-send.o
+PROGRAM_OBJS += remote-testsvn.o
 PROGRAM_OBJS += sh-i18n--envsubst.o
 PROGRAM_OBJS += shell.o
-PROGRAM_OBJS += remote-testsvn.o
 
 # Binary suffix, set to .exe for Windows builds
 X =
@@ -709,9 +709,9 @@ TEST_BUILTINS_OBJS += test-dump-untracked-cache.o
 TEST_BUILTINS_OBJS += test-example-decorate.o
 TEST_BUILTINS_OBJS += test-genrandom.o
 TEST_BUILTINS_OBJS += test-genzeros.o
+TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-hash.o
 TEST_BUILTINS_OBJS += test-hashmap.o
-TEST_BUILTINS_OBJS += test-hash-speed.o
 TEST_BUILTINS_OBJS += test-index-version.o
 TEST_BUILTINS_OBJS += test-json-writer.o
 TEST_BUILTINS_OBJS += test-lazy-init-name-hash.o
@@ -737,8 +737,8 @@ TEST_BUILTINS_OBJS += test-revision-walking.o
 TEST_BUILTINS_OBJS += test-run-command.o
 TEST_BUILTINS_OBJS += test-scrap-cache-tree.o
 TEST_BUILTINS_OBJS += test-serve-v2.o
-TEST_BUILTINS_OBJS += test-sha1.o
 TEST_BUILTINS_OBJS += test-sha1-array.o
+TEST_BUILTINS_OBJS += test-sha1.o
 TEST_BUILTINS_OBJS += test-sha256.o
 TEST_BUILTINS_OBJS += test-sigchain.o
 TEST_BUILTINS_OBJS += test-strcmp-offset.o
@@ -748,10 +748,10 @@ TEST_BUILTINS_OBJS += test-submodule-nested-repo-config.o
 TEST_BUILTINS_OBJS += test-subprocess.o
 TEST_BUILTINS_OBJS += test-trace2.o
 TEST_BUILTINS_OBJS += test-urlmatch-normalization.o
-TEST_BUILTINS_OBJS += test-xml-encode.o
 TEST_BUILTINS_OBJS += test-wildmatch.o
 TEST_BUILTINS_OBJS += test-windows-named-pipe.o
 TEST_BUILTINS_OBJS += test-write-cache.o
+TEST_BUILTINS_OBJS += test-xml-encode.o
 
 # Do not add more tests here unless they have extra dependencies. Add
 # them in TEST_BUILTINS_OBJS above.
@@ -788,10 +788,10 @@ OTHER_PROGRAMS = git$X
 
 # what test wrappers are needed and 'install' will install, in bindir
 BINDIR_PROGRAMS_NEED_X += git
-BINDIR_PROGRAMS_NEED_X += git-upload-pack
 BINDIR_PROGRAMS_NEED_X += git-receive-pack
-BINDIR_PROGRAMS_NEED_X += git-upload-archive
 BINDIR_PROGRAMS_NEED_X += git-shell
+BINDIR_PROGRAMS_NEED_X += git-upload-archive
+BINDIR_PROGRAMS_NEED_X += git-upload-pack
 
 BINDIR_PROGRAMS_NO_X += git-cvsserver
 
@@ -831,9 +831,9 @@ LIB_OBJS += advice.o
 LIB_OBJS += alias.o
 LIB_OBJS += alloc.o
 LIB_OBJS += apply.o
-LIB_OBJS += archive.o
 LIB_OBJS += archive-tar.o
 LIB_OBJS += archive-zip.o
+LIB_OBJS += archive.o
 LIB_OBJS += argv-array.o
 LIB_OBJS += attr.o
 LIB_OBJS += base85.o
@@ -849,9 +849,9 @@ LIB_OBJS += checkout.o
 LIB_OBJS += color.o
 LIB_OBJS += column.o
 LIB_OBJS += combine-diff.o
-LIB_OBJS += commit.o
 LIB_OBJS += commit-graph.o
 LIB_OBJS += commit-reach.o
+LIB_OBJS += commit.o
 LIB_OBJS += compat/obstack.o
 LIB_OBJS += compat/terminal.o
 LIB_OBJS += config.o
@@ -865,17 +865,17 @@ LIB_OBJS += ctype.o
 LIB_OBJS += date.o
 LIB_OBJS += decorate.o
 LIB_OBJS += delta-islands.o
+LIB_OBJS += diff-delta.o
+LIB_OBJS += diff-lib.o
+LIB_OBJS += diff-no-index.o
+LIB_OBJS += diff.o
 LIB_OBJS += diffcore-break.o
 LIB_OBJS += diffcore-delta.o
 LIB_OBJS += diffcore-order.o
 LIB_OBJS += diffcore-pickaxe.o
 LIB_OBJS += diffcore-rename.o
-LIB_OBJS += diff-delta.o
-LIB_OBJS += diff-lib.o
-LIB_OBJS += diff-no-index.o
-LIB_OBJS += diff.o
-LIB_OBJS += dir.o
 LIB_OBJS += dir-iterator.o
+LIB_OBJS += dir.o
 LIB_OBJS += editor.o
 LIB_OBJS += entry.o
 LIB_OBJS += environment.o
@@ -893,7 +893,6 @@ LIB_OBJS += gpg-interface.o
 LIB_OBJS += graph.o
 LIB_OBJS += grep.o
 LIB_OBJS += hashmap.o
-LIB_OBJS += linear-assignment.o
 LIB_OBJS += help.o
 LIB_OBJS += hex.o
 LIB_OBJS += ident.o
@@ -903,9 +902,10 @@ LIB_OBJS += kwset.o
 LIB_OBJS += levenshtein.o
 LIB_OBJS += line-log.o
 LIB_OBJS += line-range.o
-LIB_OBJS += list-objects.o
-LIB_OBJS += list-objects-filter.o
+LIB_OBJS += linear-assignment.o
 LIB_OBJS += list-objects-filter-options.o
+LIB_OBJS += list-objects-filter.o
+LIB_OBJS += list-objects.o
 LIB_OBJS += ll-merge.o
 LIB_OBJS += lockfile.o
 LIB_OBJS += log-tree.o
@@ -914,31 +914,31 @@ LIB_OBJS += mailinfo.o
 LIB_OBJS += mailmap.o
 LIB_OBJS += match-trees.o
 LIB_OBJS += mem-pool.o
-LIB_OBJS += merge.o
 LIB_OBJS += merge-blobs.o
 LIB_OBJS += merge-recursive.o
+LIB_OBJS += merge.o
 LIB_OBJS += mergesort.o
 LIB_OBJS += midx.o
 LIB_OBJS += name-hash.o
 LIB_OBJS += negotiator/default.o
 LIB_OBJS += negotiator/skipping.o
-LIB_OBJS += notes.o
 LIB_OBJS += notes-cache.o
 LIB_OBJS += notes-merge.o
 LIB_OBJS += notes-utils.o
+LIB_OBJS += notes.o
 LIB_OBJS += object.o
 LIB_OBJS += oidmap.o
 LIB_OBJS += oidset.o
-LIB_OBJS += packfile.o
-LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-bitmap-write.o
+LIB_OBJS += pack-bitmap.o
 LIB_OBJS += pack-check.o
 LIB_OBJS += pack-objects.o
 LIB_OBJS += pack-revindex.o
 LIB_OBJS += pack-write.o
+LIB_OBJS += packfile.o
 LIB_OBJS += pager.o
-LIB_OBJS += parse-options.o
 LIB_OBJS += parse-options-cb.o
+LIB_OBJS += parse-options.o
 LIB_OBJS += patch-delta.o
 LIB_OBJS += patch-ids.o
 LIB_OBJS += path.o
@@ -955,8 +955,9 @@ LIB_OBJS += quote.o
 LIB_OBJS += range-diff.o
 LIB_OBJS += reachable.o
 LIB_OBJS += read-cache.o
-LIB_OBJS += rebase.o
 LIB_OBJS += rebase-interactive.o
+LIB_OBJS += rebase.o
+LIB_OBJS += ref-filter.o
 LIB_OBJS += reflog-walk.o
 LIB_OBJS += refs.o
 LIB_OBJS += refs/files-backend.o
@@ -964,7 +965,6 @@ LIB_OBJS += refs/iterator.o
 LIB_OBJS += refs/packed-backend.o
 LIB_OBJS += refs/ref-cache.o
 LIB_OBJS += refspec.o
-LIB_OBJS += ref-filter.o
 LIB_OBJS += remote.o
 LIB_OBJS += replace-object.o
 LIB_OBJS += repo-settings.o
@@ -979,8 +979,8 @@ LIB_OBJS += serve.o
 LIB_OBJS += server-info.o
 LIB_OBJS += setup.o
 LIB_OBJS += sha1-array.o
-LIB_OBJS += sha1-lookup.o
 LIB_OBJS += sha1-file.o
+LIB_OBJS += sha1-lookup.o
 LIB_OBJS += sha1-name.o
 LIB_OBJS += shallow.o
 LIB_OBJS += sideband.o
@@ -990,9 +990,9 @@ LIB_OBJS += stable-qsort.o
 LIB_OBJS += strbuf.o
 LIB_OBJS += streaming.o
 LIB_OBJS += string-list.o
-LIB_OBJS += submodule.o
-LIB_OBJS += submodule-config.o
 LIB_OBJS += sub-process.o
+LIB_OBJS += submodule-config.o
+LIB_OBJS += submodule.o
 LIB_OBJS += symlinks.o
 LIB_OBJS += tag.o
 LIB_OBJS += tempfile.o
@@ -1011,11 +1011,11 @@ LIB_OBJS += trace2/tr2_tgt_normal.o
 LIB_OBJS += trace2/tr2_tgt_perf.o
 LIB_OBJS += trace2/tr2_tls.o
 LIB_OBJS += trailer.o
-LIB_OBJS += transport.o
 LIB_OBJS += transport-helper.o
+LIB_OBJS += transport.o
 LIB_OBJS += tree-diff.o
-LIB_OBJS += tree.o
 LIB_OBJS += tree-walk.o
+LIB_OBJS += tree.o
 LIB_OBJS += unpack-trees.o
 LIB_OBJS += upload-pack.o
 LIB_OBJS += url.o
@@ -1055,9 +1055,9 @@ BUILTIN_OBJS += builtin/checkout.o
 BUILTIN_OBJS += builtin/clean.o
 BUILTIN_OBJS += builtin/clone.o
 BUILTIN_OBJS += builtin/column.o
+BUILTIN_OBJS += builtin/commit-graph.o
 BUILTIN_OBJS += builtin/commit-tree.o
 BUILTIN_OBJS += builtin/commit.o
-BUILTIN_OBJS += builtin/commit-graph.o
 BUILTIN_OBJS += builtin/config.o
 BUILTIN_OBJS += builtin/count-objects.o
 BUILTIN_OBJS += builtin/credential.o
@@ -1088,13 +1088,13 @@ BUILTIN_OBJS += builtin/ls-remote.o
 BUILTIN_OBJS += builtin/ls-tree.o
 BUILTIN_OBJS += builtin/mailinfo.o
 BUILTIN_OBJS += builtin/mailsplit.o
-BUILTIN_OBJS += builtin/merge.o
 BUILTIN_OBJS += builtin/merge-base.o
 BUILTIN_OBJS += builtin/merge-file.o
 BUILTIN_OBJS += builtin/merge-index.o
 BUILTIN_OBJS += builtin/merge-ours.o
 BUILTIN_OBJS += builtin/merge-recursive.o
 BUILTIN_OBJS += builtin/merge-tree.o
+BUILTIN_OBJS += builtin/merge.o
 BUILTIN_OBJS += builtin/mktag.o
 BUILTIN_OBJS += builtin/mktree.o
 BUILTIN_OBJS += builtin/multi-pack-index.o
@@ -1114,9 +1114,9 @@ BUILTIN_OBJS += builtin/read-tree.o
 BUILTIN_OBJS += builtin/rebase.o
 BUILTIN_OBJS += builtin/receive-pack.o
 BUILTIN_OBJS += builtin/reflog.o
-BUILTIN_OBJS += builtin/remote.o
 BUILTIN_OBJS += builtin/remote-ext.o
 BUILTIN_OBJS += builtin/remote-fd.o
+BUILTIN_OBJS += builtin/remote.o
 BUILTIN_OBJS += builtin/repack.o
 BUILTIN_OBJS += builtin/replace.o
 BUILTIN_OBJS += builtin/rerere.o
@@ -2335,16 +2335,16 @@ reconfigure config.mak.autogen: config.status
 endif
 
 XDIFF_OBJS += xdiff/xdiffi.o
-XDIFF_OBJS += xdiff/xprepare.o
-XDIFF_OBJS += xdiff/xutils.o
 XDIFF_OBJS += xdiff/xemit.o
+XDIFF_OBJS += xdiff/xhistogram.o
 XDIFF_OBJS += xdiff/xmerge.o
 XDIFF_OBJS += xdiff/xpatience.o
-XDIFF_OBJS += xdiff/xhistogram.o
+XDIFF_OBJS += xdiff/xprepare.o
+XDIFF_OBJS += xdiff/xutils.o
 
+VCSSVN_OBJS += vcs-svn/fast_export.o
 VCSSVN_OBJS += vcs-svn/line_buffer.o
 VCSSVN_OBJS += vcs-svn/sliding_window.o
-VCSSVN_OBJS += vcs-svn/fast_export.o
 VCSSVN_OBJS += vcs-svn/svndiff.o
 VCSSVN_OBJS += vcs-svn/svndump.o
 
@@ -3152,9 +3152,10 @@ endif
 #
 ALL_COMMANDS = $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS)
 ALL_COMMANDS += git
+ALL_COMMANDS += git-citool
+ALL_COMMANDS += git-gui
 ALL_COMMANDS += gitk
 ALL_COMMANDS += gitweb
-ALL_COMMANDS += git-gui git-citool
 
 .PHONY: check-docs
 check-docs::
-- 
cgit v1.3


From b309a9710899dab2f76455526f573a90fad5d13c Mon Sep 17 00:00:00 2001
From: Denton Liu <liu.denton@gmail.com>
Date: Tue, 7 Apr 2020 10:28:00 -0400
Subject: reset: extract reset_head() from rebase

Continue the process of lib-ifying the autostash code. In a future
commit, this will be used to implement `--autostash` in other builtins.

This patch is best viewed with `--color-moved`.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Makefile         |   1 +
 builtin/rebase.c | 139 +-----------------------------------------------------
 reset.c          | 140 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 reset.h          |  20 ++++++++
 4 files changed, 162 insertions(+), 138 deletions(-)
 create mode 100644 reset.c
 create mode 100644 reset.h

(limited to 'Makefile')

diff --git a/Makefile b/Makefile
index f709fc3f77..338fb55b73 100644
--- a/Makefile
+++ b/Makefile
@@ -970,6 +970,7 @@ LIB_OBJS += replace-object.o
 LIB_OBJS += repo-settings.o
 LIB_OBJS += repository.o
 LIB_OBJS += rerere.o
+LIB_OBJS += reset.o
 LIB_OBJS += resolve-undo.o
 LIB_OBJS += revision.o
 LIB_OBJS += run-command.o
diff --git a/builtin/rebase.c b/builtin/rebase.c
index 5532286142..48ef36bd10 100644
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -27,6 +27,7 @@
 #include "branch.h"
 #include "sequencer.h"
 #include "rebase-interactive.h"
+#include "reset.h"
 
 #define DEFAULT_REFLOG_ACTION "rebase"
 
@@ -766,144 +767,6 @@ static void add_var(struct strbuf *buf, const char *name, const char *value)
 	}
 }
 
-#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
-
-#define RESET_HEAD_DETACH (1<<0)
-#define RESET_HEAD_HARD (1<<1)
-#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
-#define RESET_HEAD_REFS_ONLY (1<<3)
-#define RESET_ORIG_HEAD (1<<4)
-
-static 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;
-	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;
-}
-
 static int move_to_original_branch(struct rebase_options *opts)
 {
 	struct strbuf orig_head_reflog = STRBUF_INIT, head_reflog = STRBUF_INIT;
diff --git a/reset.c b/reset.c
new file mode 100644
index 0000000000..79b683bffa
--- /dev/null
+++ b/reset.c
@@ -0,0 +1,140 @@
+#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;
+	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;
+
+}
diff --git a/reset.h b/reset.h
new file mode 100644
index 0000000000..12f83c78e2
--- /dev/null
+++ b/reset.h
@@ -0,0 +1,20 @@
+#ifndef RESET_H
+#define RESET_H
+
+#include "hash.h"
+#include "repository.h"
+
+#define GIT_REFLOG_ACTION_ENVIRONMENT "GIT_REFLOG_ACTION"
+
+#define RESET_HEAD_DETACH (1<<0)
+#define RESET_HEAD_HARD (1<<1)
+#define RESET_HEAD_RUN_POST_CHECKOUT_HOOK (1<<2)
+#define RESET_HEAD_REFS_ONLY (1<<3)
+#define RESET_ORIG_HEAD (1<<4)
+
+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);
+
+#endif
-- 
cgit v1.3