git/builtin-reset.c
Jeff King 49b9362fd3 git-reset: refuse to do hard reset in a bare repository
It makes no sense since there is no working tree. A soft
reset should be fine, though.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-02 02:28:54 -08:00

295 lines
7.2 KiB
C

/*
* "git reset" builtin command
*
* Copyright (c) 2007 Carlos Rica
*
* Based on git-reset.sh, which is
*
* Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
*/
#include "cache.h"
#include "tag.h"
#include "object.h"
#include "commit.h"
#include "run-command.h"
#include "refs.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"
static const char builtin_reset_usage[] =
"git-reset [--mixed | --soft | --hard] [-q] [<commit-ish>] [ [--] <paths>...]";
static char *args_to_str(const char **argv)
{
char *buf = NULL;
unsigned long len, space = 0, nr = 0;
for (; *argv; argv++) {
len = strlen(*argv);
ALLOC_GROW(buf, nr + 1 + len, space);
if (nr)
buf[nr++] = ' ';
memcpy(buf + nr, *argv, len);
nr += len;
}
ALLOC_GROW(buf, nr + 1, space);
buf[nr] = '\0';
return buf;
}
static inline int is_merge(void)
{
return !access(git_path("MERGE_HEAD"), F_OK);
}
static int unmerged_files(void)
{
int i;
read_cache();
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (ce_stage(ce))
return 1;
}
return 0;
}
static int reset_index_file(const unsigned char *sha1, int is_hard_reset)
{
int i = 0;
const char *args[6];
args[i++] = "read-tree";
args[i++] = "-v";
args[i++] = "--reset";
if (is_hard_reset)
args[i++] = "-u";
args[i++] = sha1_to_hex(sha1);
args[i] = NULL;
return run_command_v_opt(args, RUN_GIT_CMD);
}
static void print_new_head_line(struct commit *commit)
{
const char *hex, *dots = "...", *body;
hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
if (!hex) {
hex = sha1_to_hex(commit->object.sha1);
dots = "";
}
printf("HEAD is now at %s%s", hex, dots);
body = strstr(commit->buffer, "\n\n");
if (body) {
const char *eol;
size_t len;
body += 2;
eol = strchr(body, '\n');
len = eol ? eol - body : strlen(body);
printf(" %.*s\n", (int) len, body);
}
else
printf("\n");
}
static int update_index_refresh(int fd, struct lock_file *index_lock)
{
int result;
if (!index_lock) {
index_lock = xcalloc(1, sizeof(struct lock_file));
fd = hold_locked_index(index_lock, 1);
}
if (read_cache() < 0)
return error("Could not read index");
result = refresh_cache(0) ? 1 : 0;
if (write_cache(fd, active_cache, active_nr) ||
close(fd) ||
commit_locked_index(index_lock))
return error ("Could not refresh index");
return result;
}
static void update_index_from_diff(struct diff_queue_struct *q,
struct diff_options *opt, void *data)
{
int i;
int *discard_flag = data;
/* do_diff_cache() mangled the index */
discard_cache();
*discard_flag = 1;
read_cache();
for (i = 0; i < q->nr; i++) {
struct diff_filespec *one = q->queue[i]->one;
if (one->mode) {
struct cache_entry *ce;
ce = make_cache_entry(one->mode, one->sha1, one->path,
0, 0);
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
ADD_CACHE_OK_TO_REPLACE);
} else
remove_file_from_cache(one->path);
}
}
static int read_from_tree(const char *prefix, const char **argv,
unsigned char *tree_sha1)
{
struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
int index_fd, index_was_discarded = 0;
struct diff_options opt;
memset(&opt, 0, sizeof(opt));
diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
opt.output_format = DIFF_FORMAT_CALLBACK;
opt.format_callback = update_index_from_diff;
opt.format_callback_data = &index_was_discarded;
index_fd = hold_locked_index(lock, 1);
index_was_discarded = 0;
read_cache();
if (do_diff_cache(tree_sha1, &opt))
return 1;
diffcore_std(&opt);
diff_flush(&opt);
diff_tree_release_paths(&opt);
if (!index_was_discarded)
/* The index is still clobbered from do_diff_cache() */
discard_cache();
return update_index_refresh(index_fd, lock);
}
static void prepend_reflog_action(const char *action, char *buf, size_t size)
{
const char *sep = ": ";
const char *rla = getenv("GIT_REFLOG_ACTION");
if (!rla)
rla = sep = "";
if (snprintf(buf, size, "%s%s%s", rla, sep, action) >= size)
warning("Reflog action message too long: %.*s...", 50, buf);
}
enum reset_type { MIXED, SOFT, HARD, NONE };
static const char *reset_type_names[] = { "mixed", "soft", "hard", NULL };
int cmd_reset(int argc, const char **argv, const char *prefix)
{
int i = 1, reset_type = NONE, update_ref_status = 0, quiet = 0;
const char *rev = "HEAD";
unsigned char sha1[20], *orig = NULL, sha1_orig[20],
*old_orig = NULL, sha1_old_orig[20];
struct commit *commit;
char *reflog_action, msg[1024];
git_config(git_default_config);
reflog_action = args_to_str(argv);
setenv("GIT_REFLOG_ACTION", reflog_action, 0);
while (i < argc) {
if (!strcmp(argv[i], "--mixed")) {
reset_type = MIXED;
i++;
}
else if (!strcmp(argv[i], "--soft")) {
reset_type = SOFT;
i++;
}
else if (!strcmp(argv[i], "--hard")) {
reset_type = HARD;
i++;
}
else if (!strcmp(argv[i], "-q")) {
quiet = 1;
i++;
}
else
break;
}
if (i < argc && argv[i][0] != '-')
rev = argv[i++];
if (get_sha1(rev, sha1))
die("Failed to resolve '%s' as a valid ref.", rev);
commit = lookup_commit_reference(sha1);
if (!commit)
die("Could not parse object '%s'.", rev);
hashcpy(sha1, commit->object.sha1);
if (i < argc && !strcmp(argv[i], "--"))
i++;
else if (i < argc && argv[i][0] == '-')
usage(builtin_reset_usage);
/* git reset tree [--] paths... can be used to
* load chosen paths from the tree into the index without
* affecting the working tree nor HEAD. */
if (i < argc) {
if (reset_type == MIXED)
warning("--mixed option is deprecated with paths.");
else if (reset_type != NONE)
die("Cannot do %s reset with paths.",
reset_type_names[reset_type]);
return read_from_tree(prefix, argv + i, sha1);
}
if (reset_type == NONE)
reset_type = MIXED; /* by default */
if (reset_type == HARD && is_bare_repository())
die("hard reset makes no sense in a bare repository");
/* Soft reset does not touch the index file nor the working tree
* at all, but requires them in a good order. Other resets reset
* the index file to the tree object we are switching to. */
if (reset_type == SOFT) {
if (is_merge() || unmerged_files())
die("Cannot do a soft reset in the middle of a merge.");
}
else if (reset_index_file(sha1, (reset_type == HARD)))
die("Could not reset index file to revision '%s'.", rev);
/* Any resets update HEAD to the head being switched to,
* saving the previous head in ORIG_HEAD before. */
if (!get_sha1("ORIG_HEAD", sha1_old_orig))
old_orig = sha1_old_orig;
if (!get_sha1("HEAD", sha1_orig)) {
orig = sha1_orig;
prepend_reflog_action("updating ORIG_HEAD", msg, sizeof(msg));
update_ref(msg, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
}
else if (old_orig)
delete_ref("ORIG_HEAD", old_orig);
prepend_reflog_action("updating HEAD", msg, sizeof(msg));
update_ref_status = update_ref(msg, "HEAD", sha1, orig, 0, MSG_ON_ERR);
switch (reset_type) {
case HARD:
if (!update_ref_status && !quiet)
print_new_head_line(commit);
break;
case SOFT: /* Nothing else to do. */
break;
case MIXED: /* Report what has not been updated. */
update_index_refresh(0, NULL);
break;
}
unlink(git_path("MERGE_HEAD"));
unlink(git_path("rr-cache/MERGE_RR"));
unlink(git_path("MERGE_MSG"));
unlink(git_path("SQUASH_MSG"));
free(reflog_action);
return update_ref_status;
}