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Merge branch 'hn/history-squash' into jch 

The experimental 'git history' command has been taught a new 'squash'
subcommand to fold a range of commits into a single commit, with any
descendants replayed on top.

* hn/history-squash:
  history: re-edit a squash with every message
  sequencer: share the squash message marker helpers and flags
  history: add squash subcommand to fold a range
  history: give commit_tree_ext a message template
  history: extract helper for a commit's parent tree
jch
Junio C Hamano 2026-07-25 14:27:12 -07:00
parent 12eaa188a7 9a8107a378
commit 5450abbeb6
9 changed files with 1412 additions and 72 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Documentation/config/advice.adoc
View File

@ -59,6 +59,10 @@ all advice messages.
forceDeleteBranch::
Shown when the user tries to delete a not fully merged
branch without the force option set.
historyUpdateRefs::
Shown when `git history squash` refuses because a ref points
into the range being folded, to tell the user about
`--update-refs=head`.
ignoredHook::
Shown when a hook is ignored because the hook is not
set as executable.

55
Documentation/git-history.adoc
View File

@ -12,6 +12,7 @@ git history drop <commit> [--dry-run] [--update-refs=(branches|head)] [--empty=(
git history fixup <commit> [--dry-run] [--update-refs=(branches|head)] [--reedit-message] [--empty=(drop|keep|abort)]
git history reword <commit> [--dry-run] [--update-refs=(branches|head)]
git history split <commit> [--dry-run] [--update-refs=(branches|head)] [--] [<pathspec>...]
git history squash [--dry-run] [--update-refs=(branches|head)] [--reedit-message] <revision-range>

DESCRIPTION
-----------
@ -43,8 +44,11 @@ at once.
LIMITATIONS
-----------

This command does not (yet) work with histories that contain merges. You
should use linkgit:git-rebase[1] with the `--rebase-merges` flag instead.
This command does not (yet) replay merge commits onto the rewritten
history: if a commit that would be replayed is a merge, the operation is
rejected, and you should use linkgit:git-rebase[1] with the
`--rebase-merges` flag instead. The `squash` subcommand can still fold a
merge that lies inside the range, as long as the range has a single base.

Furthermore, the command does not support operations that can result in merge
conflicts. This limitation is by design as history rewrites are not intended to
@ -113,6 +117,50 @@ linkgit:gitglossary[7].
It is invalid to select either all or no hunks, as that would lead to
one of the commits becoming empty.

`squash <revision-range>`::
Fold all commits in _<revision-range>_ into the oldest commit of that
range. The resulting commit keeps the oldest commit's authorship and
takes the tree of the range's newest commit, so the whole range
collapses into a single commit. Commits above the range are replayed
on top of the result.
+
The range is given in the usual `<base>..<tip>` form, where _<base>_ is
the commit just below the oldest commit to squash. For example, `git
history squash HEAD~3..HEAD` folds the three most recent commits into
one, and `git history squash HEAD~5..HEAD~2` squashes an interior range
while leaving the two newest commits in place. Several revisions may be
given, for example `HEAD~3..HEAD ^topic` to additionally exclude what is
already on `topic`. Rev-list options may also be given, but any that would
change how the range is walked are overridden with a warning.
+
The oldest commit's message is preserved by default, except that an `amend!`
commit targeting it replaces its message. With `--reedit-message`, an editor
opens pre-filled with the messages of all the folded commits so you can
combine them. A merge commit inside the range is folded like any other, but
the range must have a single base, so a range that reaches more than one entry
point (for example a side branch that forked before the range and was later
merged into it) is rejected.
+
A `fixup!`, `squash!`, or `amend!` commit is refused unless the commit it
targets is also in the range, so the fold does not silently absorb a
marker meant for a commit outside it. As an exception, a range made up entirely
of markers for one target is combined into a single commit, keeping the last
`amend!` message if there is one.
+
With `--reedit-message` the template mirrors `git rebase -i --autosquash`:
each `fixup!`, `squash!`, or `amend!` is grouped under the commit it
targets rather than shown in commit order. A `fixup!` message is dropped
(commented out in full), a `squash!` keeps its body with only the marker
subject commented, and an `amend!` replaces its target's message, unless
a `squash!` folded into that target first, in which case it keeps its
body like a `squash!`.
+
A branch or tag that points at a commit inside the range would be left
dangling once those commits are folded away, so with the default
`--update-refs=branches` the command refuses. Rerun with
`--update-refs=head` to rewrite only the current branch and leave such
refs pointing at the old commits.

OPTIONS
-------

@ -123,7 +171,8 @@ OPTIONS
ref updates is generally safe.

`--reedit-message`::
Open an editor to modify the target commit's message.
Open an editor to modify the rewritten commit's message. For `squash`
the editor is pre-filled with the messages of all the folded commits.

`--empty=(drop|keep|abort)`::
Control what happens when a commit becomes empty as a result of the

1
advice.c
View File

@ -58,6 +58,7 @@ static struct {
[ADVICE_FETCH_SHOW_FORCED_UPDATES] = { "fetchShowForcedUpdates" },
[ADVICE_FORCE_DELETE_BRANCH] = { "forceDeleteBranch" },
[ADVICE_GRAFT_FILE_DEPRECATED] = { "graftFileDeprecated" },
[ADVICE_HISTORY_UPDATE_REFS] = { "historyUpdateRefs" },
[ADVICE_IGNORED_HOOK] = { "ignoredHook" },
[ADVICE_IMPLICIT_IDENTITY] = { "implicitIdentity" },
[ADVICE_MERGE_CONFLICT] = { "mergeConflict" },

1
advice.h
View File

@ -25,6 +25,7 @@ enum advice_type {
ADVICE_FETCH_SHOW_FORCED_UPDATES,
ADVICE_FORCE_DELETE_BRANCH,
ADVICE_GRAFT_FILE_DEPRECATED,
ADVICE_HISTORY_UPDATE_REFS,
ADVICE_IGNORED_HOOK,
ADVICE_IMPLICIT_IDENTITY,
ADVICE_MERGE_CONFLICT,

552
builtin/history.c
View File

@ -1,6 +1,7 @@
#define USE_THE_REPOSITORY_VARIABLE

#include "builtin.h"
#include "advice.h"
#include "cache-tree.h"
#include "commit.h"
#include "commit-reach.h"
@ -34,6 +35,8 @@
N_("git history reword <commit> [--dry-run] [--update-refs=(branches|head)]")
#define GIT_HISTORY_SPLIT_USAGE \
N_("git history split <commit> [--dry-run] [--update-refs=(branches|head)] [--] [<pathspec>...]")
#define GIT_HISTORY_SQUASH_USAGE \
N_("git history squash [--dry-run] [--update-refs=(branches|head)] [--reedit-message] <revision-range>")

static void change_data_free(void *util, const char *str UNUSED)
{
@ -108,6 +111,7 @@ enum commit_tree_flags {
static int commit_tree_ext(struct repository *repo,
const char *action,
struct commit *commit_with_message,
const char *message_template,
const struct commit_list *parents,
const struct object_id *old_tree,
const struct object_id *new_tree,
@ -137,13 +141,16 @@ static int commit_tree_ext(struct repository *repo,
original_author = xmemdupz(ptr, len);
find_commit_subject(original_message, &original_body);

if (!message_template)
message_template = original_body;

if (flags & COMMIT_TREE_EDIT_MESSAGE) {
ret = fill_commit_message(repo, old_tree, new_tree,
original_body, action, &commit_message);
message_template, action, &commit_message);
if (ret < 0)
goto out;
} else {
strbuf_addstr(&commit_message, original_body);
strbuf_addstr(&commit_message, message_template);
}

original_extra_headers = read_commit_extra_headers(commit_with_message,
@ -164,6 +171,25 @@ out:
return ret;
}

static int first_parent_tree_oid(struct repository *repo,
struct commit *commit,
struct object_id *out)
{
struct commit *parent = commit->parents ? commit->parents->item : NULL;

if (!parent) {
oidcpy(out, repo->hash_algo->empty_tree);
return 0;
}

if (repo_parse_commit(repo, parent))
return error(_("unable to parse parent commit %s"),
oid_to_hex(&parent->object.oid));

oidcpy(out, &repo_get_commit_tree(repo, parent)->object.oid);
return 0;
}

static int commit_tree_with_edited_message(struct repository *repo,
const char *action,
struct commit *original,
@ -171,23 +197,13 @@ static int commit_tree_with_edited_message(struct repository *repo,
{
struct object_id parent_tree_oid;
const struct object_id *tree_oid;
struct commit *parent;

tree_oid = &repo_get_commit_tree(repo, original)->object.oid;

parent = original->parents ? original->parents->item : NULL;
if (parent) {
if (repo_parse_commit(repo, parent)) {
return error(_("unable to parse parent commit %s"),
oid_to_hex(&parent->object.oid));
}
if (first_parent_tree_oid(repo, original, &parent_tree_oid) < 0)
return -1;

parent_tree_oid = repo_get_commit_tree(repo, parent)->object.oid;
} else {
oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree);
}

return commit_tree_ext(repo, action, original, original->parents,
return commit_tree_ext(repo, action, original, NULL, original->parents,
&parent_tree_oid, tree_oid, out, COMMIT_TREE_EDIT_MESSAGE);
}

@ -475,18 +491,10 @@ static int commit_became_empty(struct repository *repo,
struct commit *original,
struct tree *result)
{
struct commit *parent = original->parents ? original->parents->item : NULL;
struct object_id parent_tree_oid;

if (parent) {
if (repo_parse_commit(repo, parent))
return error(_("unable to parse parent of %s"),
oid_to_hex(&original->object.oid));

parent_tree_oid = repo_get_commit_tree(repo, parent)->object.oid;
} else {
oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree);
}
if (first_parent_tree_oid(repo, original, &parent_tree_oid) < 0)
return -1;

return oideq(&result->object.oid, &parent_tree_oid);
}
@ -674,7 +682,7 @@ static int cmd_history_fixup(int argc,
goto out;

if (!skip_commit) {
ret = commit_tree_ext(repo, "fixup", original, original->parents,
ret = commit_tree_ext(repo, "fixup", original, NULL, original->parents,
&original_tree->object.oid, &merge_result.tree->object.oid,
&rewritten, flags);
if (ret < 0) {
@ -830,16 +838,9 @@ static int split_commit(struct repository *repo,
struct tree *split_tree;
int ret;

if (original->parents) {
if (repo_parse_commit(repo, original->parents->item)) {
ret = error(_("unable to parse parent commit %s"),
oid_to_hex(&original->parents->item->object.oid));
goto out;
}

parent_tree_oid = *get_commit_tree_oid(original->parents->item);
} else {
oidcpy(&parent_tree_oid, repo->hash_algo->empty_tree);
if (first_parent_tree_oid(repo, original, &parent_tree_oid) < 0) {
ret = -1;
goto out;
}
original_commit_tree_oid = get_commit_tree_oid(original);

@ -892,7 +893,7 @@ static int split_commit(struct repository *repo,
* The first commit is constructed from the split-out tree. The base
* that shall be diffed against is the parent of the original commit.
*/
ret = commit_tree_ext(repo, "split-out", original, original->parents, &parent_tree_oid,
ret = commit_tree_ext(repo, "split-out", original, NULL, original->parents, &parent_tree_oid,
&split_tree->object.oid, &first_commit, COMMIT_TREE_EDIT_MESSAGE);
if (ret < 0) {
ret = error(_("failed writing first commit"));
@ -909,7 +910,7 @@ static int split_commit(struct repository *repo,
old_tree_oid = &repo_get_commit_tree(repo, first_commit)->object.oid;
new_tree_oid = &repo_get_commit_tree(repo, original)->object.oid;

ret = commit_tree_ext(repo, "split-out", original, parents, old_tree_oid,
ret = commit_tree_ext(repo, "split-out", original, NULL, parents, old_tree_oid,
new_tree_oid, &second_commit, COMMIT_TREE_EDIT_MESSAGE);
if (ret < 0) {
ret = error(_("failed writing second commit"));
@ -1006,6 +1007,479 @@ out:
return ret;
}

/*
* Resolve a "<base>..<tip>" revision range into the base commit just outside
* the range (which becomes the parent of the squashed commit), the oldest
* commit contained in the range (whose message the squash reuses), and the
* range tip (whose tree becomes the result). A merge inside the range is fine,
* but the range must have a single base and must not reach a root commit.
*/
static int resolve_squash_range(struct repository *repo,
const char **argv,
struct commit **base_out,
struct commit **oldest_out,
struct commit **tip_out,
struct oidset *interior_out)
{
struct rev_info revs;
struct commit *commit, *base = NULL, *oldest = NULL, *tip = NULL;
struct commit_list *boundaries = NULL, *b;
struct strvec args = STRVEC_INIT;
size_t i;
int ret;

repo_init_revisions(repo, &revs, NULL);
revs.reverse = 1;
revs.topo_order = 1;
revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
revs.simplify_history = 0;
revs.boundary = 1;

strvec_push(&args, "ignored");
strvec_push(&args, "--ancestry-path");
strvec_pushv(&args, argv);
setup_revisions_from_strvec(&args, &revs, NULL);
if (args.nr != 1) {
ret = error(_("unrecognized argument: %s"), args.v[1]);
goto out;
}

if (revs.reverse != 1 || revs.topo_order != 1 ||
revs.sort_order != REV_SORT_IN_GRAPH_ORDER ||
revs.simplify_history != 0 || revs.boundary != 1) {
warning(_("ignoring rev-list options that would change how the "
"range is walked"));
revs.reverse = 1;
revs.topo_order = 1;
revs.sort_order = REV_SORT_IN_GRAPH_ORDER;
revs.simplify_history = 0;
revs.boundary = 1;
}

/*
* A squash needs a base to reparent onto, so the range has to exclude
* something, as in "<base>..<tip>". A revision range with no such
* bottom commit cannot be squashed.
*/
for (i = 0; i < revs.cmdline.nr; i++)
if (revs.cmdline.rev[i].flags & UNINTERESTING)
break;
if (i == revs.cmdline.nr) {
ret = error(_("not a '<base>..<tip>' revision range"));
goto out;
}

if (prepare_revision_walk(&revs) < 0) {
ret = error(_("error preparing revisions"));
goto out;
}

/*
* Set boundary commits aside for the base check below, and put every
* in-range commit but the tip into the interior set. A ref pointing
* at an interior commit would dangle once the range is folded away.
*/
while ((commit = get_revision(&revs))) {
if (commit->object.flags & BOUNDARY) {
commit_list_insert(commit, &boundaries);
continue;
}
if (!oldest)
oldest = commit;
if (tip)
oidset_insert(interior_out, &tip->object.oid);
tip = commit;
}

if (!oldest) {
ret = error(_("the revision range is empty"));
goto out;
} else if (oldest == tip) {
ret = error(_("the revision range holds a single commit; "
"nothing to squash"));
goto out;
} else if (!oldest->parents) {
BUG("an in-range commit must have a parent");
}
base = oldest->parents->item;

/*
* A boundary other than the base is an in-range commit reaching a
* commit outside the range, so the range has more than one base.
*/
for (b = boundaries; b; b = b->next) {
if (b->item != base) {
ret = error(_("the revision range has more than one base; "
"cannot squash"));
goto out;
}
}

*base_out = base;
*oldest_out = oldest;
*tip_out = tip;
ret = 0;

out:
commit_list_free(boundaries);
reset_revision_walk();
release_revisions(&revs);
strvec_clear(&args);
return ret;
}

static const char *autosquash_target(const char *subject)
{
const char *rest;

while (skip_prefix(subject, "fixup! ", &rest) ||
skip_prefix(subject, "squash! ", &rest) ||
skip_prefix(subject, "amend! ", &rest))
subject = rest;
return subject;
}

static int reject_dangling_fixups(struct repository *repo,
struct commit *base,
struct commit *tip,
struct commit *oldest,
struct commit **msg_source,
struct commit **amend_source)
{
struct todo_list todo = TODO_LIST_INIT;
struct replay_opts opts = REPLAY_OPTS_INIT;
struct rev_info revs;
struct commit *commit, *last_amend = NULL;
struct strvec args = STRVEC_INIT;
char *dangling_subject = NULL, *dangling_target = NULL;
bool mixed_target = false, all_fixups_one_target;
bool past_oldest_group = false;
int i, ret, nr_dangling = 0;

*msg_source = oldest;
*amend_source = NULL;

repo_init_revisions(repo, &revs, NULL);
strvec_push(&args, "ignored");
strvec_push(&args, "--reverse");
strvec_push(&args, "--topo-order");
strvec_pushf(&args, "%s..%s", oid_to_hex(&base->object.oid),
oid_to_hex(&tip->object.oid));
setup_revisions_from_strvec(&args, &revs, NULL);

if (prepare_revision_walk(&revs) < 0) {
ret = error(_("error preparing revisions"));
goto out;
}
while ((commit = get_revision(&revs)))
strbuf_addf(&todo.buf, "pick %s\n",
oid_to_hex(&commit->object.oid));

if (todo_list_parse_insn_buffer(repo, &opts, todo.buf.buf, &todo) < 0 ||
todo_list_rearrange_squash(&todo) < 0) {
ret = error(_("could not check the range for fixups"));
goto out;
}

for (i = 0; i < todo.nr; i++) {
const char *message, *subject_start, *target;
char *subject;
size_t sublen;

message = repo_logmsg_reencode(repo, todo.items[i].commit,
NULL, NULL);
sublen = find_commit_subject(message, &subject_start);

if (todo.items[i].command != TODO_PICK) {
if (!past_oldest_group &&
starts_with(subject_start, "amend! "))
*amend_source = todo.items[i].commit;
repo_unuse_commit_buffer(repo, todo.items[i].commit, message);
continue;
}
if (i)
past_oldest_group = true;

subject = xmemdupz(subject_start, sublen);
target = autosquash_target(subject);
if (target != subject) {
nr_dangling++;
if (!dangling_target) {
dangling_target = xstrdup(target);
dangling_subject = xstrdup(subject);
} else if (strcmp(dangling_target, target)) {
mixed_target = true;
}
if (starts_with(subject, "amend! "))
last_amend = todo.items[i].commit;
}
free(subject);
repo_unuse_commit_buffer(repo, todo.items[i].commit, message);
}

all_fixups_one_target = nr_dangling == todo.nr && !mixed_target;
if (nr_dangling && !all_fixups_one_target) {
ret = error(_("cannot squash '%s': its target is not in the "
"range"), dangling_subject);
} else {
if (last_amend)
*msg_source = last_amend;
ret = 0;
}

out:
free(dangling_subject);
free(dangling_target);
todo_list_release(&todo);
replay_opts_release(&opts);
reset_revision_walk();
release_revisions(&revs);
strvec_clear(&args);
return ret;
}

struct interior_ref_cb {
const struct oidset *interior;
const char *name;
};

static int find_interior_ref(const struct reference *ref, void *cb_data)
{
struct interior_ref_cb *data = cb_data;

if (oidset_contains(data->interior, ref->oid)) {
data->name = xstrdup(ref->name);
return 1;
}

return 0;
}

static bool amend_replaces_target(struct todo_list *todo, int target)
{
int i;

for (i = target + 1; i < todo->nr &&
todo->items[i].command != TODO_PICK; i++) {
if (todo->items[i].command == TODO_SQUASH)
return false;
if (todo->items[i].flags & TODO_REPLACE_FIXUP_MSG)
return true;
}
return false;
}

static int build_squash_message(struct repository *repo,
struct commit *base,
struct commit *tip,
struct strbuf *out)
{
struct rev_info revs;
struct commit *commit;
struct strvec args = STRVEC_INIT;
struct todo_list todo = TODO_LIST_INIT;
struct replay_opts opts = REPLAY_OPTS_INIT;
int i, nr_commits, ret;

repo_init_revisions(repo, &revs, NULL);
strvec_push(&args, "ignored");
strvec_push(&args, "--reverse");
strvec_push(&args, "--topo-order");
strvec_pushf(&args, "%s..%s", oid_to_hex(&base->object.oid),
oid_to_hex(&tip->object.oid));
setup_revisions_from_strvec(&args, &revs, NULL);

if (prepare_revision_walk(&revs) < 0) {
ret = error(_("error preparing revisions"));
goto out;
}

while ((commit = get_revision(&revs)))
strbuf_addf(&todo.buf, "pick %s\n",
oid_to_hex(&commit->object.oid));

if (todo_list_parse_insn_buffer(repo, &opts, todo.buf.buf, &todo) < 0 ||
todo_list_rearrange_squash(&todo) < 0) {
ret = error(_("could not prepare the squash message"));
goto out;
}

nr_commits = todo.nr;
for (i = 0; i < nr_commits; i++) {
struct todo_item *item = &todo.items[i];
const char *message, *body;
size_t commented_len;
bool skip, squashing;

squashing = item->command == TODO_SQUASH ||
(item->flags & TODO_REPLACE_FIXUP_MSG);
if (item->command == TODO_PICK)
skip = amend_replaces_target(&todo, i);
else
skip = !squashing;

message = repo_logmsg_reencode(repo, item->commit, NULL, NULL);
find_commit_subject(message, &body);

if (skip)
commented_len = strlen(body);
else if (squashing)
commented_len = squash_subject_comment_len(body, 1);
else
commented_len = 0;

if (!i)
add_squash_combination_header(out, nr_commits);
strbuf_addch(out, '\n');
add_squash_message_header(out, i + 1, skip);
strbuf_addstr(out, "\n\n");
strbuf_add_commented_lines(out, body, commented_len, comment_line_str);
strbuf_addstr(out, body + commented_len);
strbuf_complete_line(out);

repo_unuse_commit_buffer(repo, item->commit, message);
}

ret = 0;

out:
todo_list_release(&todo);
replay_opts_release(&opts);
reset_revision_walk();
release_revisions(&revs);
strvec_clear(&args);
return ret;
}

static int cmd_history_squash(int argc,
const char **argv,
const char *prefix,
struct repository *repo)
{
const char * const usage[] = {
GIT_HISTORY_SQUASH_USAGE,
NULL,
};
enum ref_action action = REF_ACTION_DEFAULT;
enum commit_tree_flags flags = 0;
int dry_run = 0;
struct option options[] = {
OPT_CALLBACK_F(0, "update-refs", &action, "(branches|head)",
N_("control which refs should be updated"),
PARSE_OPT_NONEG, parse_ref_action),
OPT_BOOL('n', "dry-run", &dry_run,
N_("perform a dry-run without updating any refs")),
OPT_BIT(0, "reedit-message", &flags,
N_("open an editor to modify the commit message"),
COMMIT_TREE_EDIT_MESSAGE),
OPT_END(),
};
struct strbuf reflog_msg = STRBUF_INIT;
struct strbuf message = STRBUF_INIT;
struct oidset interior = OIDSET_INIT;
struct commit *base, *oldest, *tip, *rewritten, *msg_source,
*amend_source;
const struct object_id *base_tree_oid, *tip_tree_oid;
const char *message_template = NULL;
struct commit_list *parents = NULL;
struct rev_info revs = { 0 };
int ret;

argc = parse_options(argc, argv, prefix, options, usage,
PARSE_OPT_KEEP_UNKNOWN_OPT);
if (!argc) {
ret = error(_("command expects a revision range"));
goto out;
}
repo_config(repo, git_default_config, NULL);

if (action == REF_ACTION_DEFAULT)
action = REF_ACTION_BRANCHES;

ret = resolve_squash_range(repo, argv, &base, &oldest, &tip,
&interior);
if (ret < 0)
goto out;

ret = reject_dangling_fixups(repo, base, tip, oldest, &msg_source,
&amend_source);
if (ret < 0)
goto out;
if (amend_source) {
const char *amend_message, *body;

amend_message = repo_logmsg_reencode(repo, amend_source,
NULL, NULL);
find_commit_subject(amend_message, &body);
body = skip_blank_lines(body + commit_subject_length(body));
strbuf_addstr(&message, body);
message_template = message.buf;
repo_unuse_commit_buffer(repo, amend_source, amend_message);
}

if (action == REF_ACTION_BRANCHES) {
struct interior_ref_cb cb = { .interior = &interior };

refs_for_each_ref(get_main_ref_store(repo),
find_interior_ref, &cb);
if (cb.name) {
ret = error(_("'%s' points into the squashed range"),
cb.name);
advise_if_enabled(ADVICE_HISTORY_UPDATE_REFS,
_("Use --update-refs=head to rewrite only "
"the current branch and leave such refs "
"untouched."));
free((char *)cb.name);
goto out;
}
}

if (flags & COMMIT_TREE_EDIT_MESSAGE) {
strbuf_reset(&message);
ret = build_squash_message(repo, base, tip, &message);
if (ret < 0)
goto out;
message_template = message.buf;
}

ret = setup_revwalk(repo, action, tip, &revs);
if (ret < 0)
goto out;

base_tree_oid = &repo_get_commit_tree(repo, base)->object.oid;
tip_tree_oid = &repo_get_commit_tree(repo, tip)->object.oid;
commit_list_append(base, &parents);

ret = commit_tree_ext(repo, "squash", msg_source, message_template,
parents,
base_tree_oid, tip_tree_oid, &rewritten, flags);
if (ret < 0) {
ret = error(_("failed writing squashed commit"));
goto out;
}

strbuf_addstr(&reflog_msg, "squash: updating ");
strbuf_join_argv(&reflog_msg, argc, argv, ' ');

ret = handle_reference_updates(&revs, action, tip, rewritten,
reflog_msg.buf, dry_run,
REPLAY_EMPTY_COMMIT_ABORT);
if (ret < 0) {
ret = error(_("failed replaying descendants"));
goto out;
}

ret = 0;

out:
strbuf_release(&reflog_msg);
strbuf_release(&message);
oidset_clear(&interior);
commit_list_free(parents);
release_revisions(&revs);
return ret;
}

static int update_worktree(struct repository *repo,
const struct commit *old_head,
const struct commit *new_head,
@ -1194,6 +1668,7 @@ int cmd_history(int argc,
GIT_HISTORY_FIXUP_USAGE,
GIT_HISTORY_REWORD_USAGE,
GIT_HISTORY_SPLIT_USAGE,
GIT_HISTORY_SQUASH_USAGE,
NULL,
};
parse_opt_subcommand_fn *fn = NULL;
@ -1202,6 +1677,7 @@ int cmd_history(int argc,
OPT_SUBCOMMAND("fixup", &fn, cmd_history_fixup),
OPT_SUBCOMMAND("reword", &fn, cmd_history_reword),
OPT_SUBCOMMAND("split", &fn, cmd_history_split),
OPT_SUBCOMMAND("squash", &fn, cmd_history_squash),
OPT_END(),
};


70
sequencer.c
View File

@ -1880,18 +1880,38 @@ static int is_pick_or_similar(enum todo_command command)
}
}

enum todo_item_flags {
TODO_EDIT_MERGE_MSG = (1 << 0),
TODO_REPLACE_FIXUP_MSG = (1 << 1),
TODO_EDIT_FIXUP_MSG = (1 << 2),
};

static const char first_commit_msg_str[] = N_("This is the 1st commit message:");
static const char nth_commit_msg_fmt[] = N_("This is the commit message #%d:");
static const char skip_first_commit_msg_str[] = N_("The 1st commit message will be skipped:");
static const char skip_nth_commit_msg_fmt[] = N_("The commit message #%d will be skipped:");
static const char combined_commit_msg_fmt[] = N_("This is a combination of %d commits.");

void add_squash_combination_header(struct strbuf *buf, int n)
{
strbuf_addf(buf, "%s ", comment_line_str);
strbuf_addf(buf, _(combined_commit_msg_fmt), n);
}

void add_squash_message_header(struct strbuf *buf, int n, int skip)
{
strbuf_addf(buf, "%s ", comment_line_str);
if (n == 1)
strbuf_addstr(buf, skip ? _(skip_first_commit_msg_str) :
_(first_commit_msg_str));
else
strbuf_addf(buf, skip ? _(skip_nth_commit_msg_fmt) :
_(nth_commit_msg_fmt), n);
}

size_t squash_subject_comment_len(const char *body, int squashing)
{
if (starts_with(body, "amend!") ||
(squashing && (starts_with(body, "squash!") ||
starts_with(body, "fixup!"))))
return commit_subject_length(body);
return 0;
}

static int is_fixup_flag(enum todo_command command, unsigned flag)
{
return command == TODO_FIXUP && ((flag & TODO_REPLACE_FIXUP_MSG) ||
@ -2005,20 +2025,13 @@ static int append_squash_message(struct strbuf *buf, const char *body,
{
struct replay_ctx *ctx = opts->ctx;
const char *fixup_msg;
size_t commented_len = 0, fixup_off;
/*
* amend is non-interactive and not normally used with fixup!
* or squash! commits, so only comment out those subjects when
* squashing commit messages.
*/
if (starts_with(body, "amend!") ||
((command == TODO_SQUASH || seen_squash(ctx)) &&
(starts_with(body, "squash!") || starts_with(body, "fixup!"))))
commented_len = commit_subject_length(body);
size_t commented_len, fixup_off;

strbuf_addf(buf, "\n%s ", comment_line_str);
strbuf_addf(buf, _(nth_commit_msg_fmt),
++ctx->current_fixup_count + 1);
commented_len = squash_subject_comment_len(body,
command == TODO_SQUASH || seen_squash(ctx));

strbuf_addch(buf, '\n');
add_squash_message_header(buf, ++ctx->current_fixup_count + 1, 0);
strbuf_addstr(buf, "\n\n");
strbuf_add_commented_lines(buf, body, commented_len, comment_line_str);
/* buf->buf may be reallocated so store an offset into the buffer */
@ -2083,9 +2096,8 @@ static int update_squash_messages(struct repository *r,
eol = !starts_with(buf.buf, comment_line_str) ?
buf.buf : strchrnul(buf.buf, '\n');

strbuf_addf(&header, "%s ", comment_line_str);
strbuf_addf(&header, _(combined_commit_msg_fmt),
ctx->current_fixup_count + 2);
add_squash_combination_header(&header,
ctx->current_fixup_count + 2);
strbuf_splice(&buf, 0, eol - buf.buf, header.buf, header.len);
strbuf_release(&header);
if (is_fixup_flag(command, flag) && !seen_squash(ctx))
@ -2109,12 +2121,9 @@ static int update_squash_messages(struct repository *r,
repo_unuse_commit_buffer(r, head_commit, head_message);
return error(_("cannot write '%s'"), rebase_path_fixup_msg());
}
strbuf_addf(&buf, "%s ", comment_line_str);
strbuf_addf(&buf, _(combined_commit_msg_fmt), 2);
strbuf_addf(&buf, "\n%s ", comment_line_str);
strbuf_addstr(&buf, is_fixup_flag(command, flag) ?
_(skip_first_commit_msg_str) :
_(first_commit_msg_str));
add_squash_combination_header(&buf, 2);
strbuf_addch(&buf, '\n');
add_squash_message_header(&buf, 1, is_fixup_flag(command, flag));
strbuf_addstr(&buf, "\n\n");
if (is_fixup_flag(command, flag))
strbuf_add_commented_lines(&buf, body, strlen(body),
@ -2133,9 +2142,8 @@ static int update_squash_messages(struct repository *r,
if (command == TODO_SQUASH || is_fixup_flag(command, flag)) {
res = append_squash_message(&buf, body, command, opts, flag);
} else if (command == TODO_FIXUP) {
strbuf_addf(&buf, "\n%s ", comment_line_str);
strbuf_addf(&buf, _(skip_nth_commit_msg_fmt),
++ctx->current_fixup_count + 1);
strbuf_addch(&buf, '\n');
add_squash_message_header(&buf, ++ctx->current_fixup_count + 1, 1);
strbuf_addstr(&buf, "\n\n");
strbuf_add_commented_lines(&buf, body, strlen(body),
comment_line_str);

30
sequencer.h
View File

@ -119,6 +119,13 @@ enum todo_command {
TODO_COMMENT
};

/* Bits for the "flags" member of struct todo_item */
enum todo_item_flags {
TODO_EDIT_MERGE_MSG = (1 << 0),
TODO_REPLACE_FIXUP_MSG = (1 << 1),
TODO_EDIT_FIXUP_MSG = (1 << 2),
};

struct todo_item {
enum todo_command command;
struct commit *commit;
@ -208,6 +215,29 @@ int todo_list_rearrange_squash(struct todo_list *todo_list);
*/
void append_signoff(struct strbuf *msgbuf, size_t ignore_footer, unsigned flag);

/*
* Append the "This is a combination of N commits." banner that "git rebase
* -i" writes at the top of a squashed commit's message, commented out with
* the comment character.
*/
void add_squash_combination_header(struct strbuf *buf, int n);

/*
* Append the header (1-based N) that "git rebase -i" writes above each message
* when squashing, commented out with the comment character. With SKIP it reads
* "The ... commit message will be skipped" for a message that is dropped (a
* fixup), otherwise "This is the ... commit message".
*/
void add_squash_message_header(struct strbuf *buf, int n, int skip);

/*
* Return the length of the leading subject of BODY when it should be commented
* out in a squash message, or 0 otherwise. An "amend!" subject always
* qualifies; "squash!" and "fixup!" subjects only when SQUASHING, since a
* plain fixup chain keeps them.
*/
size_t squash_subject_comment_len(const char *body, int squashing);

void append_conflicts_hint(struct index_state *istate,
struct strbuf *msgbuf, enum commit_msg_cleanup_mode cleanup_mode);
enum commit_msg_cleanup_mode get_cleanup_mode(const char *cleanup_arg,

1
t/meson.build
View File

@ -405,6 +405,7 @@ integration_tests = [
't3452-history-split.sh',
't3453-history-fixup.sh',
't3454-history-drop.sh',
't3455-history-squash.sh',
't3500-cherry.sh',
't3501-revert-cherry-pick.sh',
't3502-cherry-pick-merge.sh',

770
t/t3455-history-squash.sh Executable file
View File

@ -0,0 +1,770 @@
#!/bin/sh

test_description='tests for git-history squash subcommand'

. ./test-lib.sh

stage_file () {
printf "%s\n" "$1" >file &&
git add file
}

commit_with_message () {
printf "%b" "$1" >msg &&
git commit --allow-empty -qF msg
}

check_commit_count () {
git rev-list --count "$1" >actual &&
echo "$2" >expect &&
test_cmp expect actual
}

check_log_subjects () {
git log --format="%s" "$1" >actual &&
cat >expect &&
test_cmp expect actual
}

check_log_messages () {
git log --format="%B" "$1" >actual &&
cat >expect &&
test_cmp expect actual
}

test_expect_success 'setup linear history touching two files' '
test_commit base file a &&
git tag start &&
test_commit --no-tag one other x &&
test_commit --no-tag two file c &&
test_commit three file d
'

test_expect_success 'errors on missing range argument' '
test_must_fail git history squash 2>err &&
test_grep "expects a revision range" err
'

test_expect_success 'errors on an empty range' '
test_must_fail git history squash HEAD..HEAD 2>err &&
test_grep "the revision range is empty" err
'

test_expect_success 'errors on a single revision that is not a range' '
test_must_fail git history squash HEAD 2>err &&
test_grep "not a .*range" err &&
test_must_fail git history squash HEAD~1 2>err &&
test_grep "not a .*range" err
'

test_expect_success 'errors on a range holding a single commit' '
git reset --hard three &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git history squash "HEAD^!" 2>err &&
test_grep "single commit; nothing to squash" err &&
test_cmp_rev "$head_before" HEAD
'

test_expect_success 'accepts multiple revision arguments with an exclusion' '
git reset --hard three &&
git branch -f keep HEAD~2 &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start..HEAD ^keep &&

git reflog -1 --format=%gs >actual &&
echo "squash: updating start..HEAD ^keep" >expect &&
test_cmp expect actual &&

check_log_subjects start..HEAD <<-\EOF &&
two
one
EOF
test_cmp_rev keep HEAD~1 &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&

git branch -D keep
'

test_expect_success 'squashes a branch the current branch is not on' '
git reset --hard three &&
main=$(git symbolic-ref --short HEAD) &&
head_before=$(git rev-parse HEAD) &&
git checkout -b off-history start &&
test_commit --no-tag off-one off a &&
test_commit --no-tag off-two off b &&
git checkout "$main" &&

git history squash start..off-history &&

check_commit_count start..off-history 1 &&
test_cmp_rev "$head_before" HEAD &&

git branch -D off-history
'

test_expect_success 'squashes a range into a single commit without changing the tree' '
git reset --hard three &&
head_before=$(git rev-parse HEAD) &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash --dry-run start.. >out &&
predicted=$(awk "/^update refs\/heads\// {print \$3}" out) &&
test_cmp_rev "$head_before" HEAD &&

git history squash start.. &&

test "$predicted" = "$(git rev-parse HEAD)" &&
check_commit_count start..HEAD 1 &&
test_cmp_rev start HEAD^ &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
check_log_subjects -1 <<-\EOF &&
one
EOF
git reflog >reflog &&
test_grep "squash: updating" reflog
'

test_expect_success 'sanitizes rev-list walk options, before and after --' '
git reset --hard three &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash --date-order start.. 2>err &&
test_grep "ignoring rev-list options" err &&
test_cmp_rev start HEAD^ &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&

git reset --hard three &&
git history squash -- --reverse start.. 2>err &&
test_grep "ignoring rev-list options" err &&
test_cmp_rev start HEAD^ &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})"
'

test_expect_success 'squashes an interior range and replays descendants verbatim' '
git reset --hard three &&
final_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start..@~1 &&

check_log_subjects start..HEAD <<-\EOF &&
three
one
EOF

test_cmp_rev start HEAD~2 &&
test "$final_tree" = "$(git rev-parse HEAD^{tree})"
'

test_expect_success 'squashes when the base is the root commit' '
git reset --hard three &&
root=$(git rev-list --max-parents=0 HEAD) &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash "$root.." &&

check_commit_count "$root..HEAD" 1 &&
test_cmp_rev "$root" HEAD^ &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})"
'


test_expect_success 'folds fixups whose target is in the range' '
git reset --hard start &&
test_commit --no-tag target file b &&
git commit --allow-empty -m "fixup! target" &&
git commit --allow-empty -m "fixup! target" &&
test_commit --no-tag later file c &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
check_log_subjects -1 <<-\EOF
target
EOF
'

test_expect_success 'refuses a below-range fixup! after an in-range commit' '
git reset --hard start &&
test_commit --no-tag inside file b &&
test_commit --no-tag "fixup! outside" file c &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git history squash start.. 2>err &&
test_grep "target is not in the range" err &&
test_cmp_rev "$head_before" HEAD
'

test_expect_success 'combines a run of fixups for one commit below the range' '
git reset --hard start &&
stage_file b && git commit -m "fixup! base" &&
stage_file c && git commit -m "fixup! base" &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
check_log_subjects -1 <<-\EOF
fixup! base
EOF
'

test_expect_success 'combining below-range fixups keeps the last amend! message' '
git reset --hard start &&
stage_file b && git commit -m "fixup! base" &&
stage_file c &&
commit_with_message "amend! base\n\namended body\n" &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
check_log_messages -1 <<-\EOF
amend! base

amended body

EOF
'

test_expect_success 'refuses fixups for two different commits below the range' '
git reset --hard start &&
stage_file b && git commit -m "fixup! aaa" &&
stage_file c && git commit -m "fixup! bbb" &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git history squash start.. 2>err &&
test_grep "target is not in the range" err &&
test_cmp_rev "$head_before" HEAD
'

test_expect_success 'the last amend! for the oldest commit replaces its message' '
git reset --hard start &&
test_commit --no-tag marker-oldest file b &&
git commit --allow-empty -m "squash! marker-oldest" &&
commit_with_message "amend! marker-oldest\n\nearlier message\n" &&
commit_with_message \
"amend! marker-oldest\n\namended subject\n\namended body\n" &&
test_commit --no-tag marker-later file c &&
commit_with_message "amend! marker-later\n\nwrong message\n" &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
check_log_messages -1 <<-\EOF
amended subject

amended body

EOF
'

test_expect_success 'preserves authorship of the oldest commit' '
git reset --hard start &&
GIT_AUTHOR_NAME=Squasher GIT_AUTHOR_EMAIL=squash@example.com \
test_commit --no-tag oldest file b &&
test_commit newest file c &&

git history squash start.. &&

git log -1 --format="%an <%ae>" >actual &&
echo "Squasher <squash@example.com>" >expect &&
test_cmp expect actual
'

test_expect_success '--reedit-message offers every folded-in message' '
git reset --hard start &&
stage_file b &&
git commit -m "re-one subject" -m "re-one body line" &&
test_commit --no-tag re-two file c &&
test_commit re-three file d &&

write_script editor <<-\EOF &&
cat "$1" >edited &&
echo combined >"$1"
EOF
test_set_editor "$(pwd)/editor" &&
git history squash --reedit-message start.. &&

cat >expect <<-EOF &&
# This is a combination of 3 commits.
# This is the 1st commit message:

re-one subject

re-one body line

# This is the commit message #2:

re-two

# This is the commit message #3:

re-three

# Please enter the commit message for the squash changes. Lines starting
# with ${SQ}#${SQ} will be ignored, and an empty message aborts the commit.
# Changes to be committed:
# modified: file
#
EOF
test_cmp expect edited &&
check_log_subjects -1 <<-\EOF
combined
EOF
'

test_expect_success '--reedit-message handles fixup!, squash! and amend! like rebase' '
git reset --hard start &&
test_commit --no-tag mark-base file b &&
stage_file c &&
commit_with_message "fixup! mark-base\n\nfixup body\n" &&
stage_file d &&
commit_with_message "squash! mark-base\n\nsquash remark\n" &&
stage_file e &&
commit_with_message "amend! mark-base\n\namended message\n" &&

write_script editor <<-\EOF &&
cat "$1" >edited
EOF
test_set_editor "$(pwd)/editor" &&
git history squash --reedit-message start.. &&

cat >expect <<-EOF &&
# This is a combination of 4 commits.
# This is the 1st commit message:

mark-base

# The commit message #2 will be skipped:

# fixup! mark-base
#
# fixup body

# This is the commit message #3:

# squash! mark-base

squash remark

# This is the commit message #4:

# amend! mark-base

amended message

# Please enter the commit message for the squash changes. Lines starting
# with ${SQ}#${SQ} will be ignored, and an empty message aborts the commit.
# Changes to be committed:
# modified: file
#
EOF
test_cmp expect edited &&
check_log_messages -1 <<-\EOF
mark-base

squash remark

amended message

EOF
'

test_expect_success '--reedit-message groups fixups under their targets' '
git reset --hard start &&
test_commit --no-tag alpha file a1 &&
test_commit --no-tag beta file b1 &&
stage_file a2 &&
commit_with_message "fixup! alpha\n" &&
stage_file b2 &&
commit_with_message "fixup! beta\n" &&

write_script editor <<-\EOF &&
cat "$1" >edited
EOF
test_set_editor "$(pwd)/editor" &&
git history squash --reedit-message start.. &&

cat >expect <<-EOF &&
# This is a combination of 4 commits.
# This is the 1st commit message:

alpha

# The commit message #2 will be skipped:

# fixup! alpha

# This is the commit message #3:

beta

# The commit message #4 will be skipped:

# fixup! beta

# Please enter the commit message for the squash changes. Lines starting
# with ${SQ}#${SQ} will be ignored, and an empty message aborts the commit.
# Changes to be committed:
# modified: file
#
EOF
test_cmp expect edited
'

test_expect_success '--reedit-message lets amend! replace its target message' '
git reset --hard start &&
test_commit --no-tag mark-base file b &&
stage_file c &&
commit_with_message "amend! mark-base\n\namended message\n" &&
stage_file d &&
commit_with_message "squash! mark-base\n\nsquash remark\n" &&

write_script editor <<-\EOF &&
cat "$1" >edited
EOF
test_set_editor "$(pwd)/editor" &&
git history squash --reedit-message start.. &&

cat >expect <<-EOF &&
# This is a combination of 3 commits.
# The 1st commit message will be skipped:

# mark-base

# This is the commit message #2:

# amend! mark-base

amended message

# This is the commit message #3:

# squash! mark-base

squash remark

# Please enter the commit message for the squash changes. Lines starting
# with ${SQ}#${SQ} will be ignored, and an empty message aborts the commit.
# Changes to be committed:
# modified: file
#
EOF
test_cmp expect edited &&
check_log_messages -1 <<-\EOF
amended message

squash remark

EOF
'

test_expect_success '--reedit-message aborts on an empty message' '
git reset --hard three &&
head_before=$(git rev-parse HEAD) &&

write_script editor <<-\EOF &&
>"$1"
EOF
test_set_editor "$(pwd)/editor" &&
test_must_fail git history squash --reedit-message start.. &&

test_cmp_rev "$head_before" HEAD
'

test_expect_success '--update-refs=head only moves HEAD' '
git reset --hard three &&
git branch -f other HEAD &&
other_before=$(git rev-parse other) &&

git history squash --update-refs=head start.. &&

check_commit_count start..HEAD 1 &&
test_cmp_rev "$other_before" other
'

test_expect_success 'refuses to fold a range a ref points into' '
git reset --hard three &&
git branch -f mid HEAD~1 &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git history squash start.. 2>err &&
test_grep "error: .* points into the squashed range" err &&
test_grep "hint: .*--update-refs=head" err &&
test_cmp_rev "$head_before" HEAD &&

git branch -D mid
'

test_expect_success 'advice.historyUpdateRefs silences the hint' '
git reset --hard three &&
git branch -f mid HEAD~1 &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git -c advice.historyUpdateRefs=false \
history squash start.. 2>err &&
test_grep "points into the squashed range" err &&
test_grep ! "hint:" err &&
test_cmp_rev "$head_before" HEAD &&

git branch -D mid
'

test_expect_success '--update-refs=head folds past a ref pointing into the range' '
git reset --hard three &&
git branch -f mid HEAD~1 &&
mid_before=$(git rev-parse mid) &&

git history squash --update-refs=head start.. &&

check_commit_count start..HEAD 1 &&
test_cmp_rev "$mid_before" mid &&

git branch -D mid
'

test_expect_success 'refuses to fold a range a tag points into' '
git reset --hard three &&
git tag -f mark HEAD~1 &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git history squash start.. 2>err &&
test_grep "refs/tags/mark" err &&
test_grep "points into the squashed range" err &&
test_cmp_rev "$head_before" HEAD &&

git tag -d mark
'

test_expect_success 'squashes a range whose internal merge has a single base' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
test_commit --no-tag before-side file b &&
git checkout -b inner-side &&
test_commit --no-tag on-inner-side inner x &&
git checkout "$main" &&
test_commit --no-tag after-side file c &&
git merge --no-ff -m merge inner-side &&
git branch -D inner-side &&
test_commit --no-tag after-merge file d &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
check_log_subjects -1 <<-\EOF &&
before-side
EOF
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
test_path_is_file inner
'

test_expect_success 'folds a merge of a branch that forked at the base' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
git checkout -b base-fork-side &&
test_commit --no-tag base-fork-side side x &&
git checkout "$main" &&
test_commit --no-tag base-fork-main file b &&
git merge --no-ff -m "merge base-fork-side" base-fork-side &&
git branch -D base-fork-side &&
test_commit --no-tag base-fork-tail file c &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
test_cmp_rev start HEAD^ &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
test_path_is_file side
'

test_expect_success 'refuses a merge whose other parent is outside the range' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
git checkout -b outside-parent &&
test_commit --no-tag outside-parent outside x &&
git checkout "$main" &&
test_commit --no-tag outside-main file b &&
base=$(git rev-parse HEAD) &&
test_commit --no-tag outside-mid file c &&
git merge --no-ff -m "merge outside-parent" outside-parent &&
git branch -D outside-parent &&
merged=$(git rev-parse HEAD) &&

test_must_fail git history squash "$base.." 2>err &&
test_grep "more than one base" err &&
test_cmp_rev "$merged" HEAD
'

test_expect_success 'folds a range whose tip is a merge commit' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
test_commit --no-tag tipmerge-base file b &&
git checkout -b tipmerge-side &&
test_commit --no-tag tipmerge-side side x &&
git checkout "$main" &&
test_commit --no-tag tipmerge-main file c &&
git merge --no-ff -m "merge tipmerge-side" tipmerge-side &&
git branch -D tipmerge-side &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
test_path_is_file side
'

test_expect_success 'folds a range whose base is a merge commit' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
git checkout -b basemerge-side &&
test_commit --no-tag basemerge-side side x &&
git checkout "$main" &&
test_commit --no-tag basemerge-main file b &&
git merge --no-ff -m "merge basemerge-side" basemerge-side &&
git branch -D basemerge-side &&
base=$(git rev-parse HEAD) &&
test_commit --no-tag basemerge-one file c &&
test_commit --no-tag basemerge-two file d &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash "$base.." &&

check_commit_count "$base..HEAD" 1 &&
test_cmp_rev "$base" HEAD^ &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})"
'

test_expect_success 'folds a range with two interior merges' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
test_commit --no-tag two-merge-a file a1 &&
git checkout -b two-merge-s1 &&
test_commit --no-tag two-merge-s1 s1 x &&
git checkout "$main" &&
git merge --no-ff -m "merge s1" two-merge-s1 &&
test_commit --no-tag two-merge-b file b1 &&
git checkout -b two-merge-s2 &&
test_commit --no-tag two-merge-s2 s2 y &&
git checkout "$main" &&
git merge --no-ff -m "merge s2" two-merge-s2 &&
git branch -D two-merge-s1 two-merge-s2 &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
test_path_is_file s1 &&
test_path_is_file s2
'

test_expect_success 'folds a range with a nested merge' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
git checkout -b nested-outer &&
test_commit --no-tag nested-outer outer x &&
git checkout -b nested-inner &&
test_commit --no-tag nested-inner inner y &&
git checkout nested-outer &&
git merge --no-ff -m "merge inner" nested-inner &&
git checkout "$main" &&
test_commit --no-tag nested-main file b1 &&
git merge --no-ff -m "merge outer" nested-outer &&
git branch -D nested-outer nested-inner &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
test_path_is_file outer &&
test_path_is_file inner
'

test_expect_success 'folds a range with an octopus merge' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
test_commit --no-tag octo-base file a1 &&
git checkout -b octo-1 &&
test_commit --no-tag octo-1 o1 x &&
git checkout "$main" &&
git checkout -b octo-2 &&
test_commit --no-tag octo-2 o2 y &&
git checkout "$main" &&
git merge --no-ff -m octopus octo-1 octo-2 &&
git branch -D octo-1 octo-2 &&
tip_tree=$(git rev-parse HEAD^{tree}) &&

git history squash start.. &&

check_commit_count start..HEAD 1 &&
test "$tip_tree" = "$(git rev-parse HEAD^{tree})" &&
test_path_is_file o1 &&
test_path_is_file o2
'

test_expect_success 'refuses an octopus merge with an arm forked before the base' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
git checkout -b octo-pre &&
test_commit octo-pre-side pside x &&
git checkout "$main" &&
test_commit octo-pre-main file b1 &&
octo_base=$(git rev-parse HEAD) &&
git checkout -b octo-within &&
test_commit --no-tag octo-within wside y &&
git checkout "$main" &&
git merge --no-ff -m octopus octo-pre octo-within &&
merged=$(git rev-parse HEAD) &&
git branch -D octo-pre octo-within &&

test_must_fail git history squash "$octo_base.." 2>err &&
test_grep "more than one base" err &&
test_cmp_rev "$merged" HEAD
'

test_expect_success 'refuses when a descendant above the range is a merge' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
test_commit --no-tag desc-one file b &&
test_commit --no-tag desc-two file c &&
git tag desc-tip &&
git checkout -b desc-above &&
test_commit --no-tag desc-above above x &&
git checkout "$main" &&
test_commit --no-tag desc-main file d &&
git merge --no-ff -m "merge desc-above" desc-above &&
git branch -D desc-above &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git history squash start..desc-tip 2>err &&
test_grep "merge commits is not supported" err &&
test_cmp_rev "$head_before" HEAD
'

test_expect_success 'refuses to fold a range a ref points into at a merge' '
git reset --hard start &&
main=$(git symbolic-ref --short HEAD) &&
test_commit --no-tag refmerge-base file b &&
git checkout -b refmerge-side &&
test_commit --no-tag refmerge-side side x &&
git checkout "$main" &&
test_commit --no-tag refmerge-main file c &&
git merge --no-ff -m "interior merge" refmerge-side &&
git branch -D refmerge-side &&
git branch at-merge HEAD &&
test_commit --no-tag refmerge-tail file d &&
head_before=$(git rev-parse HEAD) &&

test_must_fail git history squash start.. 2>err &&
test_grep "at-merge" err &&
test_grep "points into the squashed range" err &&
test_cmp_rev "$head_before" HEAD &&

git branch -D at-merge
'

test_done