git-commit-vandalism/builtin-checkout.c
Junio C Hamano eac5a40151 checkout --conflict=<style>: recreate merge in a non-default style
This new option does essentially the same thing as -m option when checking
unmerged paths out of the index, but it uses the specified style instead
of configured merge.conflictstyle.

Setting "merge.conflictstyle" to "diff3" is usually less useful than using
the default "merge" style, because the latter allows a conflict that
results by both sides changing the same region in a very similar way to
get simplified substancially by reducing the common lines.  However, when
one side removed a group of lines (perhaps a function was moved to some
other file) while the other side modified it, the default "merge" style
does not give any clue as to why the hunk is left conflicting.  You would
need the original to understand what is going on.

The recommended use would be not to set merge.conflictstyle variable so
that you would usually use the default "merge" style conflict, and when
the result in a path in a particular merge is too hard to understand, use
"git checkout --conflict=diff3 $path" to check it out with the original to
review what is going on.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-31 20:09:21 -07:00

724 lines
19 KiB
C

#include "cache.h"
#include "builtin.h"
#include "parse-options.h"
#include "refs.h"
#include "commit.h"
#include "tree.h"
#include "tree-walk.h"
#include "unpack-trees.h"
#include "dir.h"
#include "run-command.h"
#include "merge-recursive.h"
#include "branch.h"
#include "diff.h"
#include "revision.h"
#include "remote.h"
#include "blob.h"
#include "xdiff-interface.h"
#include "ll-merge.h"
static const char * const checkout_usage[] = {
"git checkout [options] <branch>",
"git checkout [options] [<branch>] -- <file>...",
NULL,
};
struct checkout_opts {
int quiet;
int merge;
int force;
int writeout_stage;
int writeout_error;
const char *new_branch;
int new_branch_log;
enum branch_track track;
};
static int post_checkout_hook(struct commit *old, struct commit *new,
int changed)
{
struct child_process proc;
const char *name = git_path("hooks/post-checkout");
const char *argv[5];
if (access(name, X_OK) < 0)
return 0;
memset(&proc, 0, sizeof(proc));
argv[0] = name;
argv[1] = xstrdup(sha1_to_hex(old->object.sha1));
argv[2] = xstrdup(sha1_to_hex(new->object.sha1));
argv[3] = changed ? "1" : "0";
argv[4] = NULL;
proc.argv = argv;
proc.no_stdin = 1;
proc.stdout_to_stderr = 1;
return run_command(&proc);
}
static int update_some(const unsigned char *sha1, const char *base, int baselen,
const char *pathname, unsigned mode, int stage, void *context)
{
int len;
struct cache_entry *ce;
if (S_ISGITLINK(mode))
return 0;
if (S_ISDIR(mode))
return READ_TREE_RECURSIVE;
len = baselen + strlen(pathname);
ce = xcalloc(1, cache_entry_size(len));
hashcpy(ce->sha1, sha1);
memcpy(ce->name, base, baselen);
memcpy(ce->name + baselen, pathname, len - baselen);
ce->ce_flags = create_ce_flags(len, 0);
ce->ce_mode = create_ce_mode(mode);
add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
return 0;
}
static int read_tree_some(struct tree *tree, const char **pathspec)
{
read_tree_recursive(tree, "", 0, 0, pathspec, update_some, NULL);
/* update the index with the given tree's info
* for all args, expanding wildcards, and exit
* with any non-zero return code.
*/
return 0;
}
static int skip_same_name(struct cache_entry *ce, int pos)
{
while (++pos < active_nr &&
!strcmp(active_cache[pos]->name, ce->name))
; /* skip */
return pos;
}
static int check_stage(int stage, struct cache_entry *ce, int pos)
{
while (pos < active_nr &&
!strcmp(active_cache[pos]->name, ce->name)) {
if (ce_stage(active_cache[pos]) == stage)
return 0;
pos++;
}
return error("path '%s' does not have %s version",
ce->name,
(stage == 2) ? "our" : "their");
}
static int check_all_stages(struct cache_entry *ce, int pos)
{
if (ce_stage(ce) != 1 ||
active_nr <= pos + 2 ||
strcmp(active_cache[pos+1]->name, ce->name) ||
ce_stage(active_cache[pos+1]) != 2 ||
strcmp(active_cache[pos+2]->name, ce->name) ||
ce_stage(active_cache[pos+2]) != 3)
return error("path '%s' does not have all three versions",
ce->name);
return 0;
}
static int checkout_stage(int stage, struct cache_entry *ce, int pos,
struct checkout *state)
{
while (pos < active_nr &&
!strcmp(active_cache[pos]->name, ce->name)) {
if (ce_stage(active_cache[pos]) == stage)
return checkout_entry(active_cache[pos], state, NULL);
pos++;
}
return error("path '%s' does not have %s version",
ce->name,
(stage == 2) ? "our" : "their");
}
/* NEEDSWORK: share with merge-recursive */
static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
{
unsigned long size;
enum object_type type;
if (!hashcmp(sha1, null_sha1)) {
mm->ptr = xstrdup("");
mm->size = 0;
return;
}
mm->ptr = read_sha1_file(sha1, &type, &size);
if (!mm->ptr || type != OBJ_BLOB)
die("unable to read blob object %s", sha1_to_hex(sha1));
mm->size = size;
}
static int checkout_merged(int pos, struct checkout *state)
{
struct cache_entry *ce = active_cache[pos];
const char *path = ce->name;
mmfile_t ancestor, ours, theirs;
int status;
unsigned char sha1[20];
mmbuffer_t result_buf;
if (ce_stage(ce) != 1 ||
active_nr <= pos + 2 ||
strcmp(active_cache[pos+1]->name, path) ||
ce_stage(active_cache[pos+1]) != 2 ||
strcmp(active_cache[pos+2]->name, path) ||
ce_stage(active_cache[pos+2]) != 3)
return error("path '%s' does not have all 3 versions", path);
fill_mm(active_cache[pos]->sha1, &ancestor);
fill_mm(active_cache[pos+1]->sha1, &ours);
fill_mm(active_cache[pos+2]->sha1, &theirs);
status = ll_merge(&result_buf, path, &ancestor,
&ours, "ours", &theirs, "theirs", 1);
free(ancestor.ptr);
free(ours.ptr);
free(theirs.ptr);
if (status < 0 || !result_buf.ptr) {
free(result_buf.ptr);
return error("path '%s': cannot merge", path);
}
/*
* NEEDSWORK:
* There is absolutely no reason to write this as a blob object
* and create a phoney cache entry just to leak. This hack is
* primarily to get to the write_entry() machinery that massages
* the contents to work-tree format and writes out which only
* allows it for a cache entry. The code in write_entry() needs
* to be refactored to allow us to feed a <buffer, size, mode>
* instead of a cache entry. Such a refactoring would help
* merge_recursive as well (it also writes the merge result to the
* object database even when it may contain conflicts).
*/
if (write_sha1_file(result_buf.ptr, result_buf.size,
blob_type, sha1))
die("Unable to add merge result for '%s'", path);
ce = make_cache_entry(create_ce_mode(active_cache[pos+1]->ce_mode),
sha1,
path, 2, 0);
status = checkout_entry(ce, state, NULL);
return status;
}
static int checkout_paths(struct tree *source_tree, const char **pathspec,
struct checkout_opts *opts)
{
int pos;
struct checkout state;
static char *ps_matched;
unsigned char rev[20];
int flag;
struct commit *head;
int errs = 0;
int stage = opts->writeout_stage;
int merge = opts->merge;
int newfd;
struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
newfd = hold_locked_index(lock_file, 1);
read_cache();
if (source_tree)
read_tree_some(source_tree, pathspec);
for (pos = 0; pathspec[pos]; pos++)
;
ps_matched = xcalloc(1, pos);
for (pos = 0; pos < active_nr; pos++) {
struct cache_entry *ce = active_cache[pos];
pathspec_match(pathspec, ps_matched, ce->name, 0);
}
if (report_path_error(ps_matched, pathspec, 0))
return 1;
/* Any unmerged paths? */
for (pos = 0; pos < active_nr; pos++) {
struct cache_entry *ce = active_cache[pos];
if (pathspec_match(pathspec, NULL, ce->name, 0)) {
if (!ce_stage(ce))
continue;
if (opts->force) {
warning("path '%s' is unmerged", ce->name);
} else if (stage) {
errs |= check_stage(stage, ce, pos);
} else if (opts->merge) {
errs |= check_all_stages(ce, pos);
} else {
errs = 1;
error("path '%s' is unmerged", ce->name);
}
pos = skip_same_name(ce, pos) - 1;
}
}
if (errs)
return 1;
/* Now we are committed to check them out */
memset(&state, 0, sizeof(state));
state.force = 1;
state.refresh_cache = 1;
for (pos = 0; pos < active_nr; pos++) {
struct cache_entry *ce = active_cache[pos];
if (pathspec_match(pathspec, NULL, ce->name, 0)) {
if (!ce_stage(ce)) {
errs |= checkout_entry(ce, &state, NULL);
continue;
}
if (stage)
errs |= checkout_stage(stage, ce, pos, &state);
else if (merge)
errs |= checkout_merged(pos, &state);
pos = skip_same_name(ce, pos) - 1;
}
}
if (write_cache(newfd, active_cache, active_nr) ||
commit_locked_index(lock_file))
die("unable to write new index file");
resolve_ref("HEAD", rev, 0, &flag);
head = lookup_commit_reference_gently(rev, 1);
errs |= post_checkout_hook(head, head, 0);
return errs;
}
static void show_local_changes(struct object *head)
{
struct rev_info rev;
/* I think we want full paths, even if we're in a subdirectory. */
init_revisions(&rev, NULL);
rev.abbrev = 0;
rev.diffopt.output_format |= DIFF_FORMAT_NAME_STATUS;
add_pending_object(&rev, head, NULL);
run_diff_index(&rev, 0);
}
static void describe_detached_head(char *msg, struct commit *commit)
{
struct strbuf sb;
strbuf_init(&sb, 0);
parse_commit(commit);
pretty_print_commit(CMIT_FMT_ONELINE, commit, &sb, 0, NULL, NULL, 0, 0);
fprintf(stderr, "%s %s... %s\n", msg,
find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV), sb.buf);
strbuf_release(&sb);
}
static int reset_tree(struct tree *tree, struct checkout_opts *o, int worktree)
{
struct unpack_trees_options opts;
struct tree_desc tree_desc;
memset(&opts, 0, sizeof(opts));
opts.head_idx = -1;
opts.update = worktree;
opts.skip_unmerged = !worktree;
opts.reset = 1;
opts.merge = 1;
opts.fn = oneway_merge;
opts.verbose_update = !o->quiet;
opts.src_index = &the_index;
opts.dst_index = &the_index;
parse_tree(tree);
init_tree_desc(&tree_desc, tree->buffer, tree->size);
switch (unpack_trees(1, &tree_desc, &opts)) {
case -2:
o->writeout_error = 1;
/*
* We return 0 nevertheless, as the index is all right
* and more importantly we have made best efforts to
* update paths in the work tree, and we cannot revert
* them.
*/
case 0:
return 0;
default:
return 128;
}
}
struct branch_info {
const char *name; /* The short name used */
const char *path; /* The full name of a real branch */
struct commit *commit; /* The named commit */
};
static void setup_branch_path(struct branch_info *branch)
{
struct strbuf buf;
strbuf_init(&buf, 0);
strbuf_addstr(&buf, "refs/heads/");
strbuf_addstr(&buf, branch->name);
branch->path = strbuf_detach(&buf, NULL);
}
static int merge_working_tree(struct checkout_opts *opts,
struct branch_info *old, struct branch_info *new)
{
int ret;
struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
int newfd = hold_locked_index(lock_file, 1);
read_cache();
if (opts->force) {
ret = reset_tree(new->commit->tree, opts, 1);
if (ret)
return ret;
} else {
struct tree_desc trees[2];
struct tree *tree;
struct unpack_trees_options topts;
memset(&topts, 0, sizeof(topts));
topts.head_idx = -1;
topts.src_index = &the_index;
topts.dst_index = &the_index;
topts.msgs.not_uptodate_file = "You have local changes to '%s'; cannot switch branches.";
refresh_cache(REFRESH_QUIET);
if (unmerged_cache()) {
error("you need to resolve your current index first");
return 1;
}
/* 2-way merge to the new branch */
topts.update = 1;
topts.merge = 1;
topts.gently = opts->merge;
topts.verbose_update = !opts->quiet;
topts.fn = twoway_merge;
topts.dir = xcalloc(1, sizeof(*topts.dir));
topts.dir->show_ignored = 1;
topts.dir->exclude_per_dir = ".gitignore";
tree = parse_tree_indirect(old->commit->object.sha1);
init_tree_desc(&trees[0], tree->buffer, tree->size);
tree = parse_tree_indirect(new->commit->object.sha1);
init_tree_desc(&trees[1], tree->buffer, tree->size);
ret = unpack_trees(2, trees, &topts);
if (ret == -1) {
/*
* Unpack couldn't do a trivial merge; either
* give up or do a real merge, depending on
* whether the merge flag was used.
*/
struct tree *result;
struct tree *work;
if (!opts->merge)
return 1;
parse_commit(old->commit);
/* Do more real merge */
/*
* We update the index fully, then write the
* tree from the index, then merge the new
* branch with the current tree, with the old
* branch as the base. Then we reset the index
* (but not the working tree) to the new
* branch, leaving the working tree as the
* merged version, but skipping unmerged
* entries in the index.
*/
add_files_to_cache(NULL, NULL, 0);
work = write_tree_from_memory();
ret = reset_tree(new->commit->tree, opts, 1);
if (ret)
return ret;
merge_trees(new->commit->tree, work, old->commit->tree,
new->name, "local", &result);
ret = reset_tree(new->commit->tree, opts, 0);
if (ret)
return ret;
}
}
if (write_cache(newfd, active_cache, active_nr) ||
commit_locked_index(lock_file))
die("unable to write new index file");
if (!opts->force)
show_local_changes(&new->commit->object);
return 0;
}
static void report_tracking(struct branch_info *new)
{
struct strbuf sb = STRBUF_INIT;
struct branch *branch = branch_get(new->name);
if (!format_tracking_info(branch, &sb))
return;
fputs(sb.buf, stdout);
strbuf_release(&sb);
}
static void update_refs_for_switch(struct checkout_opts *opts,
struct branch_info *old,
struct branch_info *new)
{
struct strbuf msg;
const char *old_desc;
if (opts->new_branch) {
create_branch(old->name, opts->new_branch, new->name, 0,
opts->new_branch_log, opts->track);
new->name = opts->new_branch;
setup_branch_path(new);
}
strbuf_init(&msg, 0);
old_desc = old->name;
if (!old_desc)
old_desc = sha1_to_hex(old->commit->object.sha1);
strbuf_addf(&msg, "checkout: moving from %s to %s",
old_desc, new->name);
if (new->path) {
create_symref("HEAD", new->path, msg.buf);
if (!opts->quiet) {
if (old->path && !strcmp(new->path, old->path))
fprintf(stderr, "Already on \"%s\"\n",
new->name);
else
fprintf(stderr, "Switched to%s branch \"%s\"\n",
opts->new_branch ? " a new" : "",
new->name);
}
} else if (strcmp(new->name, "HEAD")) {
update_ref(msg.buf, "HEAD", new->commit->object.sha1, NULL,
REF_NODEREF, DIE_ON_ERR);
if (!opts->quiet) {
if (old->path)
fprintf(stderr, "Note: moving to \"%s\" which isn't a local branch\nIf you want to create a new branch from this checkout, you may do so\n(now or later) by using -b with the checkout command again. Example:\n git checkout -b <new_branch_name>\n", new->name);
describe_detached_head("HEAD is now at", new->commit);
}
}
remove_branch_state();
strbuf_release(&msg);
if (!opts->quiet && (new->path || !strcmp(new->name, "HEAD")))
report_tracking(new);
}
static int switch_branches(struct checkout_opts *opts, struct branch_info *new)
{
int ret = 0;
struct branch_info old;
unsigned char rev[20];
int flag;
memset(&old, 0, sizeof(old));
old.path = resolve_ref("HEAD", rev, 0, &flag);
old.commit = lookup_commit_reference_gently(rev, 1);
if (!(flag & REF_ISSYMREF))
old.path = NULL;
if (old.path && !prefixcmp(old.path, "refs/heads/"))
old.name = old.path + strlen("refs/heads/");
if (!new->name) {
new->name = "HEAD";
new->commit = old.commit;
if (!new->commit)
die("You are on a branch yet to be born");
parse_commit(new->commit);
}
/*
* If the new thing isn't a branch and isn't HEAD and we're
* not starting a new branch, and we want messages, and we
* weren't on a branch, and we're moving to a new commit,
* describe the old commit.
*/
if (!new->path && strcmp(new->name, "HEAD") && !opts->new_branch &&
!opts->quiet && !old.path && new->commit != old.commit)
describe_detached_head("Previous HEAD position was", old.commit);
if (!old.commit) {
if (!opts->quiet) {
fprintf(stderr, "warning: You appear to be on a branch yet to be born.\n");
fprintf(stderr, "warning: Forcing checkout of %s.\n", new->name);
}
opts->force = 1;
}
ret = merge_working_tree(opts, &old, new);
if (ret)
return ret;
update_refs_for_switch(opts, &old, new);
ret = post_checkout_hook(old.commit, new->commit, 1);
return ret || opts->writeout_error;
}
static int git_checkout_config(const char *var, const char *value, void *cb)
{
return git_xmerge_config(var, value, cb);
}
int cmd_checkout(int argc, const char **argv, const char *prefix)
{
struct checkout_opts opts;
unsigned char rev[20];
const char *arg;
struct branch_info new;
struct tree *source_tree = NULL;
char *conflict_style = NULL;
struct option options[] = {
OPT__QUIET(&opts.quiet),
OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
OPT_BOOLEAN('l', NULL, &opts.new_branch_log, "log for new branch"),
OPT_SET_INT('t', "track", &opts.track, "track",
BRANCH_TRACK_EXPLICIT),
OPT_SET_INT('2', "ours", &opts.writeout_stage, "stage",
2),
OPT_SET_INT('3', "theirs", &opts.writeout_stage, "stage",
3),
OPT_BOOLEAN('f', NULL, &opts.force, "force"),
OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
OPT_STRING(0, "conflict", &conflict_style, "style",
"conflict style (merge or diff3)"),
OPT_END(),
};
int has_dash_dash;
memset(&opts, 0, sizeof(opts));
memset(&new, 0, sizeof(new));
git_config(git_checkout_config, NULL);
opts.track = git_branch_track;
argc = parse_options(argc, argv, options, checkout_usage,
PARSE_OPT_KEEP_DASHDASH);
if (conflict_style) {
opts.merge = 1; /* implied */
git_xmerge_config("merge.conflictstyle", conflict_style, NULL);
}
if (!opts.new_branch && (opts.track != git_branch_track))
die("git checkout: --track and --no-track require -b");
if (opts.force && opts.merge)
die("git checkout: -f and -m are incompatible");
/*
* case 1: git checkout <ref> -- [<paths>]
*
* <ref> must be a valid tree, everything after the '--' must be
* a path.
*
* case 2: git checkout -- [<paths>]
*
* everything after the '--' must be paths.
*
* case 3: git checkout <something> [<paths>]
*
* With no paths, if <something> is a commit, that is to
* switch to the branch or detach HEAD at it.
*
* Otherwise <something> shall not be ambiguous.
* - If it's *only* a reference, treat it like case (1).
* - If it's only a path, treat it like case (2).
* - else: fail.
*
*/
if (argc) {
if (!strcmp(argv[0], "--")) { /* case (2) */
argv++;
argc--;
goto no_reference;
}
arg = argv[0];
has_dash_dash = (argc > 1) && !strcmp(argv[1], "--");
if (get_sha1(arg, rev)) {
if (has_dash_dash) /* case (1) */
die("invalid reference: %s", arg);
goto no_reference; /* case (3 -> 2) */
}
/* we can't end up being in (2) anymore, eat the argument */
argv++;
argc--;
if ((new.commit = lookup_commit_reference_gently(rev, 1))) {
new.name = arg;
setup_branch_path(&new);
if (resolve_ref(new.path, rev, 1, NULL))
new.commit = lookup_commit_reference(rev);
else
new.path = NULL;
parse_commit(new.commit);
source_tree = new.commit->tree;
} else
source_tree = parse_tree_indirect(rev);
if (!source_tree) /* case (1): want a tree */
die("reference is not a tree: %s", arg);
if (!has_dash_dash) {/* case (3 -> 1) */
/*
* Do not complain the most common case
* git checkout branch
* even if there happen to be a file called 'branch';
* it would be extremely annoying.
*/
if (argc)
verify_non_filename(NULL, arg);
}
else {
argv++;
argc--;
}
}
no_reference:
if (argc) {
const char **pathspec = get_pathspec(prefix, argv);
if (!pathspec)
die("invalid path specification");
/* Checkout paths */
if (opts.new_branch) {
if (argc == 1) {
die("git checkout: updating paths is incompatible with switching branches.\nDid you intend to checkout '%s' which can not be resolved as commit?", argv[0]);
} else {
die("git checkout: updating paths is incompatible with switching branches.");
}
}
if (1 < !!opts.writeout_stage + !!opts.force + !!opts.merge)
die("git checkout: --ours/--theirs, --force and --merge are incompatible when\nchecking out of the index.");
return checkout_paths(source_tree, pathspec, &opts);
}
if (new.name && !new.commit) {
die("Cannot switch branch to a non-commit.");
}
if (opts.writeout_stage)
die("--ours/--theirs is incompatible with switching branches.");
return switch_branches(&opts, &new);
}