git-commit-vandalism/builtin-branch.c
Junio C Hamano c847f53712 Detached HEAD (experimental)
This allows "git checkout v1.4.3" to dissociate the HEAD of
repository from any branch.  After this point, "git branch"
starts reporting that you are not on any branch.  You can go
back to an existing branch by saying "git checkout master", for
example.

This is still experimental.  While I think it makes sense to
allow commits on top of detached HEAD, it is rather dangerous
unless you are careful in the current form.  Next "git checkout
master" will obviously lose what you have done, so we might want
to require "git checkout -f" out of a detached HEAD if we find
that the HEAD commit is not an ancestor of any other branches.
There is no such safety valve implemented right now.

On the other hand, the reason the user did not start the ad-hoc
work on a new branch with "git checkout -b" was probably because
the work was of a throw-away nature, so the convenience of not
having that safety valve might be even better.  The user, after
accumulating some commits on top of a detached HEAD, can always
create a new branch with "git checkout -b" not to lose useful
work done while the HEAD was detached.

We'll see.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-08 03:02:11 -08:00

495 lines
12 KiB
C

/*
* Builtin "git branch"
*
* Copyright (c) 2006 Kristian Høgsberg <krh@redhat.com>
* Based on git-branch.sh by Junio C Hamano.
*/
#include "cache.h"
#include "color.h"
#include "refs.h"
#include "commit.h"
#include "builtin.h"
static const char builtin_branch_usage[] =
"git-branch [-r] (-d | -D) <branchname> | [-l] [-f] <branchname> [<start-point>] | (-m | -M) [<oldbranch>] <newbranch> | [--color | --no-color] [-r | -a] [-v [--abbrev=<length>]]";
#define REF_UNKNOWN_TYPE 0x00
#define REF_LOCAL_BRANCH 0x01
#define REF_REMOTE_BRANCH 0x02
#define REF_TAG 0x04
static const char *head;
static unsigned char head_sha1[20];
static int branch_use_color;
static char branch_colors[][COLOR_MAXLEN] = {
"\033[m", /* reset */
"", /* PLAIN (normal) */
"\033[31m", /* REMOTE (red) */
"", /* LOCAL (normal) */
"\033[32m", /* CURRENT (green) */
};
enum color_branch {
COLOR_BRANCH_RESET = 0,
COLOR_BRANCH_PLAIN = 1,
COLOR_BRANCH_REMOTE = 2,
COLOR_BRANCH_LOCAL = 3,
COLOR_BRANCH_CURRENT = 4,
};
static int parse_branch_color_slot(const char *var, int ofs)
{
if (!strcasecmp(var+ofs, "plain"))
return COLOR_BRANCH_PLAIN;
if (!strcasecmp(var+ofs, "reset"))
return COLOR_BRANCH_RESET;
if (!strcasecmp(var+ofs, "remote"))
return COLOR_BRANCH_REMOTE;
if (!strcasecmp(var+ofs, "local"))
return COLOR_BRANCH_LOCAL;
if (!strcasecmp(var+ofs, "current"))
return COLOR_BRANCH_CURRENT;
die("bad config variable '%s'", var);
}
int git_branch_config(const char *var, const char *value)
{
if (!strcmp(var, "color.branch")) {
branch_use_color = git_config_colorbool(var, value);
return 0;
}
if (!strncmp(var, "color.branch.", 13)) {
int slot = parse_branch_color_slot(var, 13);
color_parse(value, var, branch_colors[slot]);
return 0;
}
return git_default_config(var, value);
}
const char *branch_get_color(enum color_branch ix)
{
if (branch_use_color)
return branch_colors[ix];
return "";
}
static int delete_branches(int argc, const char **argv, int force, int kinds)
{
struct commit *rev, *head_rev = head_rev;
unsigned char sha1[20];
char *name = NULL;
const char *fmt, *remote;
int i;
int ret = 0;
switch (kinds) {
case REF_REMOTE_BRANCH:
fmt = "refs/remotes/%s";
remote = "remote ";
force = 1;
break;
case REF_LOCAL_BRANCH:
fmt = "refs/heads/%s";
remote = "";
break;
default:
die("cannot use -a with -d");
}
if (!force) {
head_rev = lookup_commit_reference(head_sha1);
if (!head_rev)
die("Couldn't look up commit object for HEAD");
}
for (i = 0; i < argc; i++) {
if (kinds == REF_LOCAL_BRANCH && !strcmp(head, argv[i])) {
error("Cannot delete the branch '%s' "
"which you are currently on.", argv[i]);
ret = 1;
continue;
}
if (name)
free(name);
name = xstrdup(mkpath(fmt, argv[i]));
if (!resolve_ref(name, sha1, 1, NULL)) {
error("%sbranch '%s' not found.",
remote, argv[i]);
ret = 1;
continue;
}
rev = lookup_commit_reference(sha1);
if (!rev) {
error("Couldn't look up commit object for '%s'", name);
ret = 1;
continue;
}
/* This checks whether the merge bases of branch and
* HEAD contains branch -- which means that the HEAD
* contains everything in both.
*/
if (!force &&
!in_merge_bases(rev, head_rev)) {
error("The branch '%s' is not a strict subset of "
"your current HEAD.\n"
"If you are sure you want to delete it, "
"run 'git branch -D %s'.", argv[i], argv[i]);
ret = 1;
continue;
}
if (delete_ref(name, sha1)) {
error("Error deleting %sbranch '%s'", remote,
argv[i]);
ret = 1;
} else
printf("Deleted %sbranch %s.\n", remote, argv[i]);
}
if (name)
free(name);
return(ret);
}
struct ref_item {
char *name;
unsigned int kind;
unsigned char sha1[20];
};
struct ref_list {
int index, alloc, maxwidth;
struct ref_item *list;
int kinds;
};
static int append_ref(const char *refname, const unsigned char *sha1, int flags, void *cb_data)
{
struct ref_list *ref_list = (struct ref_list*)(cb_data);
struct ref_item *newitem;
int kind = REF_UNKNOWN_TYPE;
int len;
/* Detect kind */
if (!strncmp(refname, "refs/heads/", 11)) {
kind = REF_LOCAL_BRANCH;
refname += 11;
} else if (!strncmp(refname, "refs/remotes/", 13)) {
kind = REF_REMOTE_BRANCH;
refname += 13;
} else if (!strncmp(refname, "refs/tags/", 10)) {
kind = REF_TAG;
refname += 10;
}
/* Don't add types the caller doesn't want */
if ((kind & ref_list->kinds) == 0)
return 0;
/* Resize buffer */
if (ref_list->index >= ref_list->alloc) {
ref_list->alloc = alloc_nr(ref_list->alloc);
ref_list->list = xrealloc(ref_list->list,
ref_list->alloc * sizeof(struct ref_item));
}
/* Record the new item */
newitem = &(ref_list->list[ref_list->index++]);
newitem->name = xstrdup(refname);
newitem->kind = kind;
hashcpy(newitem->sha1, sha1);
len = strlen(newitem->name);
if (len > ref_list->maxwidth)
ref_list->maxwidth = len;
return 0;
}
static void free_ref_list(struct ref_list *ref_list)
{
int i;
for (i = 0; i < ref_list->index; i++)
free(ref_list->list[i].name);
free(ref_list->list);
}
static int ref_cmp(const void *r1, const void *r2)
{
struct ref_item *c1 = (struct ref_item *)(r1);
struct ref_item *c2 = (struct ref_item *)(r2);
if (c1->kind != c2->kind)
return c1->kind - c2->kind;
return strcmp(c1->name, c2->name);
}
static void print_ref_item(struct ref_item *item, int maxwidth, int verbose,
int abbrev, int current)
{
char c;
int color;
struct commit *commit;
char subject[256];
switch (item->kind) {
case REF_LOCAL_BRANCH:
color = COLOR_BRANCH_LOCAL;
break;
case REF_REMOTE_BRANCH:
color = COLOR_BRANCH_REMOTE;
break;
default:
color = COLOR_BRANCH_PLAIN;
break;
}
c = ' ';
if (current) {
c = '*';
color = COLOR_BRANCH_CURRENT;
}
if (verbose) {
commit = lookup_commit(item->sha1);
if (commit && !parse_commit(commit))
pretty_print_commit(CMIT_FMT_ONELINE, commit, ~0,
subject, sizeof(subject), 0,
NULL, NULL, 0);
else
strcpy(subject, " **** invalid ref ****");
printf("%c %s%-*s%s %s %s\n", c, branch_get_color(color),
maxwidth, item->name,
branch_get_color(COLOR_BRANCH_RESET),
find_unique_abbrev(item->sha1, abbrev), subject);
} else {
printf("%c %s%s%s\n", c, branch_get_color(color), item->name,
branch_get_color(COLOR_BRANCH_RESET));
}
}
static void print_ref_list(int kinds, int detached, int verbose, int abbrev)
{
int i;
struct ref_list ref_list;
memset(&ref_list, 0, sizeof(ref_list));
ref_list.kinds = kinds;
for_each_ref(append_ref, &ref_list);
qsort(ref_list.list, ref_list.index, sizeof(struct ref_item), ref_cmp);
detached = (detached && (kinds & REF_LOCAL_BRANCH));
if (detached) {
struct ref_item item;
item.name = "(no branch)";
item.kind = REF_LOCAL_BRANCH;
hashcpy(item.sha1, head_sha1);
if (strlen(item.name) > ref_list.maxwidth)
ref_list.maxwidth = strlen(item.name);
print_ref_item(&item, ref_list.maxwidth, verbose, abbrev, 1);
}
for (i = 0; i < ref_list.index; i++) {
int current = !detached &&
(ref_list.list[i].kind == REF_LOCAL_BRANCH) &&
!strcmp(ref_list.list[i].name, head);
print_ref_item(&ref_list.list[i], ref_list.maxwidth, verbose,
abbrev, current);
}
free_ref_list(&ref_list);
}
static void create_branch(const char *name, const char *start_name,
unsigned char *start_sha1,
int force, int reflog)
{
struct ref_lock *lock;
struct commit *commit;
unsigned char sha1[20];
char ref[PATH_MAX], msg[PATH_MAX + 20];
snprintf(ref, sizeof ref, "refs/heads/%s", name);
if (check_ref_format(ref))
die("'%s' is not a valid branch name.", name);
if (resolve_ref(ref, sha1, 1, NULL)) {
if (!force)
die("A branch named '%s' already exists.", name);
else if (!strcmp(head, name))
die("Cannot force update the current branch.");
}
if (start_sha1)
/* detached HEAD */
hashcpy(sha1, start_sha1);
else if (get_sha1(start_name, sha1))
die("Not a valid object name: '%s'.", start_name);
if ((commit = lookup_commit_reference(sha1)) == NULL)
die("Not a valid branch point: '%s'.", start_name);
hashcpy(sha1, commit->object.sha1);
lock = lock_any_ref_for_update(ref, NULL);
if (!lock)
die("Failed to lock ref for update: %s.", strerror(errno));
if (reflog) {
log_all_ref_updates = 1;
snprintf(msg, sizeof msg, "branch: Created from %s",
start_name);
}
if (write_ref_sha1(lock, sha1, msg) < 0)
die("Failed to write ref: %s.", strerror(errno));
}
static void rename_branch(const char *oldname, const char *newname, int force)
{
char oldref[PATH_MAX], newref[PATH_MAX], logmsg[PATH_MAX*2 + 100];
unsigned char sha1[20];
if (!oldname)
die("cannot rename the curren branch while not on any.");
if (snprintf(oldref, sizeof(oldref), "refs/heads/%s", oldname) > sizeof(oldref))
die("Old branchname too long");
if (check_ref_format(oldref))
die("Invalid branch name: %s", oldref);
if (snprintf(newref, sizeof(newref), "refs/heads/%s", newname) > sizeof(newref))
die("New branchname too long");
if (check_ref_format(newref))
die("Invalid branch name: %s", newref);
if (resolve_ref(newref, sha1, 1, NULL) && !force)
die("A branch named '%s' already exists.", newname);
snprintf(logmsg, sizeof(logmsg), "Branch: renamed %s to %s",
oldref, newref);
if (rename_ref(oldref, newref, logmsg))
die("Branch rename failed");
if (!strcmp(oldname, head) && create_symref("HEAD", newref))
die("Branch renamed to %s, but HEAD is not updated!", newname);
}
int cmd_branch(int argc, const char **argv, const char *prefix)
{
int delete = 0, force_delete = 0, force_create = 0;
int rename = 0, force_rename = 0;
int verbose = 0, abbrev = DEFAULT_ABBREV, detached = 0;
int reflog = 0;
int kinds = REF_LOCAL_BRANCH;
int i;
setup_ident();
git_config(git_branch_config);
for (i = 1; i < argc; i++) {
const char *arg = argv[i];
if (arg[0] != '-')
break;
if (!strcmp(arg, "--")) {
i++;
break;
}
if (!strcmp(arg, "-d")) {
delete = 1;
continue;
}
if (!strcmp(arg, "-D")) {
delete = 1;
force_delete = 1;
continue;
}
if (!strcmp(arg, "-f")) {
force_create = 1;
continue;
}
if (!strcmp(arg, "-m")) {
rename = 1;
continue;
}
if (!strcmp(arg, "-M")) {
rename = 1;
force_rename = 1;
continue;
}
if (!strcmp(arg, "-r")) {
kinds = REF_REMOTE_BRANCH;
continue;
}
if (!strcmp(arg, "-a")) {
kinds = REF_REMOTE_BRANCH | REF_LOCAL_BRANCH;
continue;
}
if (!strcmp(arg, "-l")) {
reflog = 1;
continue;
}
if (!strncmp(arg, "--abbrev=", 9)) {
abbrev = atoi(arg+9);
continue;
}
if (!strcmp(arg, "-v")) {
verbose = 1;
continue;
}
if (!strcmp(arg, "--color")) {
branch_use_color = 1;
continue;
}
if (!strcmp(arg, "--no-color")) {
branch_use_color = 0;
continue;
}
usage(builtin_branch_usage);
}
if ((delete && rename) || (delete && force_create) ||
(rename && force_create))
usage(builtin_branch_usage);
head = xstrdup(resolve_ref("HEAD", head_sha1, 0, NULL));
if (!head)
die("Failed to resolve HEAD as a valid ref.");
if (!strcmp(head, "HEAD")) {
detached = 1;
}
else {
if (strncmp(head, "refs/heads/", 11))
die("HEAD not found below refs/heads!");
head += 11;
}
if (delete)
return delete_branches(argc - i, argv + i, force_delete, kinds);
else if (i == argc)
print_ref_list(kinds, detached, verbose, abbrev);
else if (rename && (i == argc - 1))
rename_branch(head, argv[i], force_rename);
else if (rename && (i == argc - 2))
rename_branch(argv[i], argv[i + 1], force_rename);
else if (i == argc - 1)
create_branch(argv[i], head, head_sha1, force_create, reflog);
else if (i == argc - 2)
create_branch(argv[i], argv[i+1], NULL, force_create, reflog);
else
usage(builtin_branch_usage);
return 0;
}