git/worktree.c

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#include "cache.h"
#include "repository.h"
#include "refs.h"
#include "strbuf.h"
#include "worktree.h"
#include "dir.h"
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#include "wt-status.h"
void free_worktrees(struct worktree **worktrees)
{
int i = 0;
for (i = 0; worktrees[i]; i++) {
free(worktrees[i]->path);
free(worktrees[i]->id);
free(worktrees[i]->head_ref);
free(worktrees[i]->lock_reason);
free(worktrees[i]);
}
free (worktrees);
}
/**
* Update head_sha1, head_ref and is_detached of the given worktree
*/
static void add_head_info(struct worktree *wt)
{
int flags;
const char *target;
target = refs_resolve_ref_unsafe(get_worktree_ref_store(wt),
"HEAD",
branch: fix branch renaming not updating HEADs correctly There are two bugs that sort of work together and cause problems. Let's start with one in replace_each_worktree_head_symref. Before fa099d2322 (worktree.c: kill parse_ref() in favor of refs_resolve_ref_unsafe() - 2017-04-24), this code looks like this: if (strcmp(oldref, worktrees[i]->head_ref)) continue; set_worktree_head_symref(...); After fa099d2322, it is possible that head_ref can be NULL. However, the updated code takes the wrong exit. In the error case (NULL head_ref), we should "continue;" to the next worktree. The updated code makes us _skip_ "continue;" and update HEAD anyway. The NULL head_ref is triggered by the second bug in add_head_info (in the same commit). With the flag RESOLVE_REF_READING, resolve_ref_unsafe() will abort if it cannot resolve the target ref. For orphan checkouts, HEAD always points to an unborned branch, resolving target ref will always fail. Now we have NULL head_ref. Now we always update HEAD. Correct the logic in replace_ function so that we don't accidentally update HEAD on error. As it turns out, correcting the logic bug above breaks branch renaming completely, thanks to the second bug. "git branch -[Mm]" does two steps (on a normal checkout, no orphan!): - rename the branch on disk (e.g. refs/heads/abc to refs/heads/def) - update HEAD if it points to the branch being renamed. At the second step, since the branch pointed to by HEAD (e.g. "abc") no longer exists on disk, we run into a temporary orphan checkout situation that has been just corrected to _not_ update HEAD. But we need to update HEAD since it's not actually an orphan checkout. We need to update HEAD to move out of that orphan state. Correct add_head_info(), remove RESOLVE_REF_READING flag. With the flag gone, we should always return good "head_ref" in orphan checkouts (either temporary or permanent). With good head_ref, things start to work again. Noticed-by: Nish Aravamudan <nish.aravamudan@canonical.com> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-24 10:41:24 +00:00
0,
&wt->head_oid, &flags);
if (!target)
return;
if (flags & REF_ISSYMREF)
wt->head_ref = xstrdup(target);
else
wt->is_detached = 1;
}
/**
* get the main worktree
*/
static struct worktree *get_main_worktree(void)
{
struct worktree *worktree = NULL;
struct strbuf path = STRBUF_INIT;
struct strbuf worktree_path = STRBUF_INIT;
int is_bare = 0;
strbuf_add_absolute_path(&worktree_path, get_git_common_dir());
is_bare = !strbuf_strip_suffix(&worktree_path, "/.git");
if (is_bare)
strbuf_strip_suffix(&worktree_path, "/.");
strbuf_addf(&path, "%s/HEAD", get_git_common_dir());
worktree = xcalloc(1, sizeof(*worktree));
worktree->path = strbuf_detach(&worktree_path, NULL);
worktree->is_bare = is_bare;
add_head_info(worktree);
strbuf_release(&path);
strbuf_release(&worktree_path);
return worktree;
}
static struct worktree *get_linked_worktree(const char *id)
{
struct worktree *worktree = NULL;
struct strbuf path = STRBUF_INIT;
struct strbuf worktree_path = STRBUF_INIT;
if (!id)
die("Missing linked worktree name");
strbuf_git_common_path(&path, the_repository, "worktrees/%s/gitdir", id);
if (strbuf_read_file(&worktree_path, path.buf, 0) <= 0)
/* invalid gitdir file */
goto done;
strbuf_rtrim(&worktree_path);
if (!strbuf_strip_suffix(&worktree_path, "/.git")) {
strbuf_reset(&worktree_path);
strbuf_add_absolute_path(&worktree_path, ".");
strbuf_strip_suffix(&worktree_path, "/.");
}
strbuf_reset(&path);
strbuf_addf(&path, "%s/worktrees/%s/HEAD", get_git_common_dir(), id);
worktree = xcalloc(1, sizeof(*worktree));
worktree->path = strbuf_detach(&worktree_path, NULL);
worktree->id = xstrdup(id);
add_head_info(worktree);
done:
strbuf_release(&path);
strbuf_release(&worktree_path);
return worktree;
}
static void mark_current_worktree(struct worktree **worktrees)
{
char *git_dir = absolute_pathdup(get_git_dir());
int i;
for (i = 0; worktrees[i]; i++) {
struct worktree *wt = worktrees[i];
const char *wt_git_dir = get_worktree_git_dir(wt);
if (!fspathcmp(git_dir, absolute_path(wt_git_dir))) {
wt->is_current = 1;
break;
}
}
free(git_dir);
}
static int compare_worktree(const void *a_, const void *b_)
{
const struct worktree *const *a = a_;
const struct worktree *const *b = b_;
return fspathcmp((*a)->path, (*b)->path);
}
struct worktree **get_worktrees(unsigned flags)
{
struct worktree **list = NULL;
struct strbuf path = STRBUF_INIT;
DIR *dir;
struct dirent *d;
int counter = 0, alloc = 2;
ALLOC_ARRAY(list, alloc);
list[counter++] = get_main_worktree();
strbuf_addf(&path, "%s/worktrees", get_git_common_dir());
dir = opendir(path.buf);
strbuf_release(&path);
if (dir) {
while ((d = readdir(dir)) != NULL) {
struct worktree *linked = NULL;
if (is_dot_or_dotdot(d->d_name))
continue;
if ((linked = get_linked_worktree(d->d_name))) {
ALLOC_GROW(list, counter + 1, alloc);
list[counter++] = linked;
}
}
closedir(dir);
}
ALLOC_GROW(list, counter + 1, alloc);
list[counter] = NULL;
if (flags & GWT_SORT_LINKED)
/*
* don't sort the first item (main worktree), which will
* always be the first
*/
QSORT(list + 1, counter - 1, compare_worktree);
mark_current_worktree(list);
return list;
}
const char *get_worktree_git_dir(const struct worktree *wt)
{
if (!wt)
return get_git_dir();
else if (!wt->id)
return get_git_common_dir();
else
return git_common_path("worktrees/%s", wt->id);
}
static struct worktree *find_worktree_by_suffix(struct worktree **list,
const char *suffix)
{
struct worktree *found = NULL;
int nr_found = 0, suffixlen;
suffixlen = strlen(suffix);
if (!suffixlen)
return NULL;
for (; *list && nr_found < 2; list++) {
const char *path = (*list)->path;
int pathlen = strlen(path);
int start = pathlen - suffixlen;
/* suffix must start at directory boundary */
if ((!start || (start > 0 && is_dir_sep(path[start - 1]))) &&
!fspathcmp(suffix, path + start)) {
found = *list;
nr_found++;
}
}
return nr_found == 1 ? found : NULL;
}
struct worktree *find_worktree(struct worktree **list,
const char *prefix,
const char *arg)
{
struct worktree *wt;
char *path;
char *to_free = NULL;
if ((wt = find_worktree_by_suffix(list, arg)))
return wt;
if (prefix)
arg = to_free = prefix_filename(prefix, arg);
path = real_pathdup(arg, 0);
if (!path) {
free(to_free);
return NULL;
}
for (; *list; list++)
if (!fspathcmp(path, real_path((*list)->path)))
break;
free(path);
free(to_free);
return *list;
}
int is_main_worktree(const struct worktree *wt)
{
return !wt->id;
}
const char *worktree_lock_reason(struct worktree *wt)
{
assert(!is_main_worktree(wt));
if (!wt->lock_reason_valid) {
struct strbuf path = STRBUF_INIT;
strbuf_addstr(&path, worktree_git_path(wt, "locked"));
if (file_exists(path.buf)) {
struct strbuf lock_reason = STRBUF_INIT;
if (strbuf_read_file(&lock_reason, path.buf, 0) < 0)
die_errno(_("failed to read '%s'"), path.buf);
strbuf_trim(&lock_reason);
wt->lock_reason = strbuf_detach(&lock_reason, NULL);
} else
wt->lock_reason = NULL;
wt->lock_reason_valid = 1;
strbuf_release(&path);
}
return wt->lock_reason;
}
/* convenient wrapper to deal with NULL strbuf */
static void strbuf_addf_gently(struct strbuf *buf, const char *fmt, ...)
{
va_list params;
if (!buf)
return;
va_start(params, fmt);
strbuf_vaddf(buf, fmt, params);
va_end(params);
}
int validate_worktree(const struct worktree *wt, struct strbuf *errmsg,
unsigned flags)
{
struct strbuf wt_path = STRBUF_INIT;
char *path = NULL;
int err, ret = -1;
strbuf_addf(&wt_path, "%s/.git", wt->path);
if (is_main_worktree(wt)) {
if (is_directory(wt_path.buf)) {
ret = 0;
goto done;
}
/*
* Main worktree using .git file to point to the
* repository would make it impossible to know where
* the actual worktree is if this function is executed
* from another worktree. No .git file support for now.
*/
strbuf_addf_gently(errmsg,
_("'%s' at main working tree is not the repository directory"),
wt_path.buf);
goto done;
}
/*
* Make sure "gitdir" file points to a real .git file and that
* file points back here.
*/
if (!is_absolute_path(wt->path)) {
strbuf_addf_gently(errmsg,
_("'%s' file does not contain absolute path to the working tree location"),
git_common_path("worktrees/%s/gitdir", wt->id));
goto done;
}
if (flags & WT_VALIDATE_WORKTREE_MISSING_OK &&
!file_exists(wt->path)) {
ret = 0;
goto done;
}
if (!file_exists(wt_path.buf)) {
strbuf_addf_gently(errmsg, _("'%s' does not exist"), wt_path.buf);
goto done;
}
path = xstrdup_or_null(read_gitfile_gently(wt_path.buf, &err));
if (!path) {
strbuf_addf_gently(errmsg, _("'%s' is not a .git file, error code %d"),
wt_path.buf, err);
goto done;
}
ret = fspathcmp(path, real_path(git_common_path("worktrees/%s", wt->id)));
if (ret)
strbuf_addf_gently(errmsg, _("'%s' does not point back to '%s'"),
wt->path, git_common_path("worktrees/%s", wt->id));
done:
free(path);
strbuf_release(&wt_path);
return ret;
}
void update_worktree_location(struct worktree *wt, const char *path_)
{
struct strbuf path = STRBUF_INIT;
if (is_main_worktree(wt))
BUG("can't relocate main worktree");
strbuf_realpath(&path, path_, 1);
if (fspathcmp(wt->path, path.buf)) {
write_file(git_common_path("worktrees/%s/gitdir", wt->id),
"%s/.git", path.buf);
free(wt->path);
wt->path = strbuf_detach(&path, NULL);
}
strbuf_release(&path);
}
int is_worktree_being_rebased(const struct worktree *wt,
const char *target)
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{
struct wt_status_state state;
int found_rebase;
memset(&state, 0, sizeof(state));
found_rebase = wt_status_check_rebase(wt, &state) &&
((state.rebase_in_progress ||
state.rebase_interactive_in_progress) &&
state.branch &&
starts_with(target, "refs/heads/") &&
!strcmp(state.branch, target + strlen("refs/heads/")));
free(state.branch);
free(state.onto);
return found_rebase;
}
int is_worktree_being_bisected(const struct worktree *wt,
const char *target)
{
struct wt_status_state state;
int found_rebase;
memset(&state, 0, sizeof(state));
found_rebase = wt_status_check_bisect(wt, &state) &&
state.branch &&
starts_with(target, "refs/heads/") &&
!strcmp(state.branch, target + strlen("refs/heads/"));
free(state.branch);
return found_rebase;
}
2016-04-22 13:01:33 +00:00
/*
* note: this function should be able to detect shared symref even if
* HEAD is temporarily detached (e.g. in the middle of rebase or
* bisect). New commands that do similar things should update this
* function as well.
*/
const struct worktree *find_shared_symref(const char *symref,
const char *target)
{
const struct worktree *existing = NULL;
static struct worktree **worktrees;
int i = 0;
if (worktrees)
free_worktrees(worktrees);
worktrees = get_worktrees(0);
for (i = 0; worktrees[i]; i++) {
struct worktree *wt = worktrees[i];
const char *symref_target;
struct ref_store *refs;
int flags;
if (wt->is_bare)
continue;
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if (wt->is_detached && !strcmp(symref, "HEAD")) {
if (is_worktree_being_rebased(wt, target)) {
existing = wt;
break;
}
if (is_worktree_being_bisected(wt, target)) {
existing = wt;
break;
}
2016-04-22 13:01:33 +00:00
}
refs = get_worktree_ref_store(wt);
symref_target = refs_resolve_ref_unsafe(refs, symref, 0,
NULL, &flags);
worktree: handle broken symrefs in find_shared_symref() The refs_resolve_ref_unsafe() function may return NULL even with a REF_ISSYMREF flag if a symref points to a broken ref. As a result, it's possible for find_shared_symref() to segfault when it passes NULL to strcmp(). This is hard to trigger for most code paths. We typically pass HEAD to the function as the symref to resolve, and programs like "git branch" will bail much earlier if HEAD isn't valid. I did manage to trigger it through one very obscure sequence: # You have multiple notes refs which conflict. git notes add -m base git notes --ref refs/notes/foo add -m foo # There's left-over cruft in NOTES_MERGE_REF that # makes it a broken symref (in this case we point # to a syntactically invalid ref). echo "ref: refs/heads/master.lock" >.git/NOTES_MERGE_REF # You try to merge the notes. We read the broken value in # order to complain that another notes-merge is # in-progress, but we segfault in find_shared_symref(). git notes merge refs/notes/foo This is obviously silly and almost certainly impossible to trigger accidentally, but it does show that the bug is triggerable from at least one code path. In addition, it would trigger if we saw a transient filesystem error when resolving the pointed-to ref. We can fix this by treating NULL the same as a non-matching symref. Arguably we'd prefer to know if a symref points to "refs/heads/foo", but "refs/heads/foo" is broken. But refs_resolve_ref_unsafe() isn't capable of giving us that information, so this is the best we can do. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-19 17:49:36 +00:00
if ((flags & REF_ISSYMREF) &&
symref_target && !strcmp(symref_target, target)) {
existing = wt;
break;
}
}
return existing;
}
int submodule_uses_worktrees(const char *path)
{
char *submodule_gitdir;
struct strbuf sb = STRBUF_INIT;
DIR *dir;
struct dirent *d;
int ret = 0;
struct repository_format format;
submodule_gitdir = git_pathdup_submodule(path, "%s", "");
if (!submodule_gitdir)
return 0;
/* The env would be set for the superproject. */
get_common_dir_noenv(&sb, submodule_gitdir);
free(submodule_gitdir);
/*
* The check below is only known to be good for repository format
* version 0 at the time of writing this code.
*/
strbuf_addstr(&sb, "/config");
read_repository_format(&format, sb.buf);
if (format.version != 0) {
strbuf_release(&sb);
return 1;
}
/* Replace config by worktrees. */
strbuf_setlen(&sb, sb.len - strlen("config"));
strbuf_addstr(&sb, "worktrees");
/* See if there is any file inside the worktrees directory. */
dir = opendir(sb.buf);
strbuf_release(&sb);
if (!dir)
return 0;
while ((d = readdir(dir)) != NULL) {
if (is_dot_or_dotdot(d->d_name))
continue;
ret = 1;
break;
}
closedir(dir);
return ret;
}
refs: new ref types to make per-worktree refs visible to all worktrees One of the problems with multiple worktree is accessing per-worktree refs of one worktree from another worktree. This was sort of solved by multiple ref store, where the code can open the ref store of another worktree and has access to the ref space of that worktree. The problem with this is reporting. "HEAD" in another ref space is also called "HEAD" like in the current ref space. In order to differentiate them, all the code must somehow carry the ref store around and print something like "HEAD from this ref store". But that is not feasible (or possible with a _lot_ of work). With the current design, we pass a reference around as a string (so called "refname"). Extending this design to pass a string _and_ a ref store is a nightmare, especially when handling extended SHA-1 syntax. So we do it another way. Instead of entering a separate ref space, we make refs from other worktrees available in the current ref space. So "HEAD" is always HEAD of the current worktree, but then we can have "worktrees/blah/HEAD" to denote HEAD from a worktree named "blah". This syntax coincidentally matches the underlying directory structure which makes implementation a bit easier. The main worktree has to be treated specially because well... it's special from the beginning. So HEAD from the main worktree is acccessible via the name "main-worktree/HEAD" instead of "worktrees/main/HEAD" because "main" could be just another secondary worktree. This patch also makes it possible to specify refs from one worktree in another one, e.g. git log worktrees/foo/HEAD Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-21 08:08:54 +00:00
int parse_worktree_ref(const char *worktree_ref, const char **name,
int *name_length, const char **ref)
{
if (skip_prefix(worktree_ref, "main-worktree/", &worktree_ref)) {
if (!*worktree_ref)
return -1;
if (name)
*name = NULL;
if (name_length)
*name_length = 0;
if (ref)
*ref = worktree_ref;
return 0;
}
if (skip_prefix(worktree_ref, "worktrees/", &worktree_ref)) {
const char *slash = strchr(worktree_ref, '/');
if (!slash || slash == worktree_ref || !slash[1])
return -1;
if (name)
*name = worktree_ref;
if (name_length)
*name_length = slash - worktree_ref;
if (ref)
*ref = slash + 1;
return 0;
}
return -1;
}
void strbuf_worktree_ref(const struct worktree *wt,
struct strbuf *sb,
const char *refname)
{
switch (ref_type(refname)) {
case REF_TYPE_PSEUDOREF:
case REF_TYPE_PER_WORKTREE:
if (wt && !wt->is_current) {
if (is_main_worktree(wt))
strbuf_addstr(sb, "main-worktree/");
else
strbuf_addf(sb, "worktrees/%s/", wt->id);
}
break;
case REF_TYPE_MAIN_PSEUDOREF:
case REF_TYPE_OTHER_PSEUDOREF:
break;
case REF_TYPE_NORMAL:
/*
* For shared refs, don't prefix worktrees/ or
* main-worktree/. It's not necessary and
* files-backend.c can't handle it anyway.
*/
break;
}
strbuf_addstr(sb, refname);
}
const char *worktree_ref(const struct worktree *wt, const char *refname)
{
static struct strbuf sb = STRBUF_INIT;
strbuf_reset(&sb);
strbuf_worktree_ref(wt, &sb, refname);
return sb.buf;
}
int other_head_refs(each_ref_fn fn, void *cb_data)
{
struct worktree **worktrees, **p;
int ret = 0;
worktrees = get_worktrees(0);
for (p = worktrees; *p; p++) {
struct worktree *wt = *p;
struct object_id oid;
int flag;
if (wt->is_current)
continue;
if (!refs_read_ref_full(get_main_ref_store(the_repository),
worktree_ref(wt, "HEAD"),
RESOLVE_REF_READING,
&oid, &flag))
ret = fn(worktree_ref(wt, "HEAD"), &oid, flag, cb_data);
if (ret)
break;
}
free_worktrees(worktrees);
return ret;
}