git/builtin/read-tree.c
Victoria Dye f27c170f64 read-tree: make three-way merge sparse-aware
Enable use of 'merged_sparse_dir' in 'threeway_merge'. As with two-way
merge, the contents of each conflicted sparse directory are merged without
referencing the index, avoiding sparse index expansion.

As with two-way merge, the 't/t1092-sparse-checkout-compatibility.sh' test
'read-tree --merge with edit/edit conflicts in sparse directories' confirms
that three-way merges with edit/edit changes (both with and without
conflicts) inside a sparse directory result in the correct index state or
error message. To ensure the index is not unnecessarily expanded, add
three-way merge cases to 'sparse index is not expanded: read-tree'.

Signed-off-by: Victoria Dye <vdye@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-01 12:36:01 -08:00

277 lines
7.8 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#define USE_THE_INDEX_COMPATIBILITY_MACROS
#include "cache.h"
#include "config.h"
#include "lockfile.h"
#include "object.h"
#include "tree.h"
#include "tree-walk.h"
#include "cache-tree.h"
#include "unpack-trees.h"
#include "dir.h"
#include "builtin.h"
#include "parse-options.h"
#include "resolve-undo.h"
#include "submodule.h"
#include "submodule-config.h"
static int nr_trees;
static int read_empty;
static struct tree *trees[MAX_UNPACK_TREES];
static int list_tree(struct object_id *oid)
{
struct tree *tree;
if (nr_trees >= MAX_UNPACK_TREES)
die("I cannot read more than %d trees", MAX_UNPACK_TREES);
tree = parse_tree_indirect(oid);
if (!tree)
return -1;
trees[nr_trees++] = tree;
return 0;
}
static const char * const read_tree_usage[] = {
N_("git read-tree [(-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>) [-u | -i]] [--no-sparse-checkout] [--index-output=<file>] (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
NULL
};
static int index_output_cb(const struct option *opt, const char *arg,
int unset)
{
BUG_ON_OPT_NEG(unset);
set_alternate_index_output(arg);
return 0;
}
static int exclude_per_directory_cb(const struct option *opt, const char *arg,
int unset)
{
struct unpack_trees_options *opts;
BUG_ON_OPT_NEG(unset);
opts = (struct unpack_trees_options *)opt->value;
if (!opts->update)
die("--exclude-per-directory is meaningless unless -u");
if (strcmp(arg, ".gitignore"))
die("--exclude-per-directory argument must be .gitignore");
return 0;
}
static void debug_stage(const char *label, const struct cache_entry *ce,
struct unpack_trees_options *o)
{
printf("%s ", label);
if (!ce)
printf("(missing)\n");
else if (ce == o->df_conflict_entry)
printf("(conflict)\n");
else
printf("%06o #%d %s %.8s\n",
ce->ce_mode, ce_stage(ce), ce->name,
oid_to_hex(&ce->oid));
}
static int debug_merge(const struct cache_entry * const *stages,
struct unpack_trees_options *o)
{
int i;
printf("* %d-way merge\n", o->merge_size);
debug_stage("index", stages[0], o);
for (i = 1; i <= o->merge_size; i++) {
char buf[24];
xsnprintf(buf, sizeof(buf), "ent#%d", i);
debug_stage(buf, stages[i], o);
}
return 0;
}
static int git_read_tree_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, "submodule.recurse"))
return git_default_submodule_config(var, value, cb);
return git_default_config(var, value, cb);
}
int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
{
int i, stage = 0;
struct object_id oid;
struct tree_desc t[MAX_UNPACK_TREES];
struct unpack_trees_options opts;
int prefix_set = 0;
struct lock_file lock_file = LOCK_INIT;
const struct option read_tree_options[] = {
OPT_CALLBACK_F(0, "index-output", NULL, N_("file"),
N_("write resulting index to <file>"),
PARSE_OPT_NONEG, index_output_cb),
OPT_BOOL(0, "empty", &read_empty,
N_("only empty the index")),
OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
OPT_GROUP(N_("Merging")),
OPT_BOOL('m', NULL, &opts.merge,
N_("perform a merge in addition to a read")),
OPT_BOOL(0, "trivial", &opts.trivial_merges_only,
N_("3-way merge if no file level merging required")),
OPT_BOOL(0, "aggressive", &opts.aggressive,
N_("3-way merge in presence of adds and removes")),
OPT_BOOL(0, "reset", &opts.reset,
N_("same as -m, but discard unmerged entries")),
{ OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
N_("read the tree into the index under <subdirectory>/"),
PARSE_OPT_NONEG },
OPT_BOOL('u', NULL, &opts.update,
N_("update working tree with merge result")),
OPT_CALLBACK_F(0, "exclude-per-directory", &opts,
N_("gitignore"),
N_("allow explicitly ignored files to be overwritten"),
PARSE_OPT_NONEG, exclude_per_directory_cb),
OPT_BOOL('i', NULL, &opts.index_only,
N_("don't check the working tree after merging")),
OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
OPT_BOOL(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
N_("skip applying sparse checkout filter")),
OPT_BOOL(0, "debug-unpack", &opts.debug_unpack,
N_("debug unpack-trees")),
OPT_CALLBACK_F(0, "recurse-submodules", NULL,
"checkout", "control recursive updating of submodules",
PARSE_OPT_OPTARG, option_parse_recurse_submodules_worktree_updater),
OPT__QUIET(&opts.quiet, N_("suppress feedback messages")),
OPT_END()
};
memset(&opts, 0, sizeof(opts));
opts.head_idx = -1;
opts.src_index = &the_index;
opts.dst_index = &the_index;
git_config(git_read_tree_config, NULL);
argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
read_tree_usage, 0);
prefix_set = opts.prefix ? 1 : 0;
if (1 < opts.merge + opts.reset + prefix_set)
die("Which one? -m, --reset, or --prefix?");
/* Prefix should not start with a directory separator */
if (opts.prefix && opts.prefix[0] == '/')
die("Invalid prefix, prefix cannot start with '/'");
if (opts.reset)
opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
prepare_repo_settings(the_repository);
the_repository->settings.command_requires_full_index = 0;
hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
/*
* NEEDSWORK
*
* The old index should be read anyway even if we're going to
* destroy all index entries because we still need to preserve
* certain information such as index version or split-index
* mode.
*/
if (opts.reset || opts.merge || opts.prefix) {
if (read_cache_unmerged() && (opts.prefix || opts.merge))
die(_("You need to resolve your current index first"));
stage = opts.merge = 1;
}
resolve_undo_clear();
for (i = 0; i < argc; i++) {
const char *arg = argv[i];
if (get_oid(arg, &oid))
die("Not a valid object name %s", arg);
if (list_tree(&oid) < 0)
die("failed to unpack tree object %s", arg);
stage++;
}
if (!nr_trees && !read_empty && !opts.merge)
warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
else if (nr_trees > 0 && read_empty)
die("passing trees as arguments contradicts --empty");
if (1 < opts.index_only + opts.update)
die("-u and -i at the same time makes no sense");
if ((opts.update || opts.index_only) && !opts.merge)
die("%s is meaningless without -m, --reset, or --prefix",
opts.update ? "-u" : "-i");
if (opts.update && !opts.reset)
opts.preserve_ignored = 0;
/* otherwise, opts.preserve_ignored is irrelevant */
if (opts.merge && !opts.index_only)
setup_work_tree();
if (opts.skip_sparse_checkout)
ensure_full_index(&the_index);
if (opts.merge) {
switch (stage - 1) {
case 0:
die("you must specify at least one tree to merge");
break;
case 1:
opts.fn = opts.prefix ? bind_merge : oneway_merge;
break;
case 2:
opts.fn = twoway_merge;
opts.initial_checkout = is_cache_unborn();
break;
case 3:
default:
opts.fn = threeway_merge;
break;
}
if (stage - 1 >= 3)
opts.head_idx = stage - 2;
else
opts.head_idx = 1;
}
if (opts.debug_unpack)
opts.fn = debug_merge;
cache_tree_free(&active_cache_tree);
for (i = 0; i < nr_trees; i++) {
struct tree *tree = trees[i];
parse_tree(tree);
init_tree_desc(t+i, tree->buffer, tree->size);
}
if (unpack_trees(nr_trees, t, &opts))
return 128;
if (opts.debug_unpack || opts.dry_run)
return 0; /* do not write the index out */
/*
* When reading only one tree (either the most basic form,
* "-m ent" or "--reset ent" form), we can obtain a fully
* valid cache-tree because the index must match exactly
* what came from the tree.
*/
if (nr_trees == 1 && !opts.prefix)
prime_cache_tree(the_repository,
the_repository->index,
trees[0]);
if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
die("unable to write new index file");
return 0;
}