git/merge.c

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#include "cache.h"
#include "lockfile.h"
#include "commit.h"
#include "run-command.h"
#include "resolve-undo.h"
#include "tree-walk.h"
#include "unpack-trees.h"
#include "dir.h"
static const char *merge_argument(struct commit *commit)
{
if (commit)
return oid_to_hex(&commit->object.oid);
else
return EMPTY_TREE_SHA1_HEX;
}
int try_merge_command(const char *strategy, size_t xopts_nr,
const char **xopts, struct commit_list *common,
const char *head_arg, struct commit_list *remotes)
{
struct argv_array args = ARGV_ARRAY_INIT;
int i, ret;
struct commit_list *j;
argv_array_pushf(&args, "merge-%s", strategy);
for (i = 0; i < xopts_nr; i++)
argv_array_pushf(&args, "--%s", xopts[i]);
for (j = common; j; j = j->next)
argv_array_push(&args, merge_argument(j->item));
argv_array_push(&args, "--");
argv_array_push(&args, head_arg);
for (j = remotes; j; j = j->next)
argv_array_push(&args, merge_argument(j->item));
ret = run_command_v_opt(args.argv, RUN_GIT_CMD);
argv_array_clear(&args);
discard_cache();
if (read_cache() < 0)
die(_("failed to read the cache"));
resolve_undo_clear();
return ret;
}
int checkout_fast_forward(const struct object_id *head,
const struct object_id *remote,
int overwrite_ignore)
{
struct tree *trees[MAX_UNPACK_TREES];
struct unpack_trees_options opts;
struct tree_desc t[MAX_UNPACK_TREES];
int i, nr_trees = 0;
struct dir_struct dir;
struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
refresh_cache(REFRESH_QUIET);
lockfile: LOCK_REPORT_ON_ERROR The "libify sequencer" topic stopped passing the die_on_error option to hold_locked_index(), and this lost an error message from "git merge --ff-only $commit" when there are competing updates in progress. The command still exits with a non-zero status, but that is not of much help for an interactive user. The last thing the command says is "Updating $from..$to". We used to follow it with a big error message that makes it clear that "merge --ff-only" did not succeed. What is sad is that we should have noticed this regression while reviewing the change. It was clear that the update to the checkout_fast_forward() function made a failing hold_locked_index() silent, but the only caller of the checkout_fast_forward() function had this comment: if (checkout_fast_forward(from, to, 1)) - exit(128); /* the callee should have complained already */ + return -1; /* the callee should have complained already */ which clearly contradicted the assumption X-<. Add a new option LOCK_REPORT_ON_ERROR that can be passed instead of LOCK_DIE_ON_ERROR to the hold_lock*() family of functions and teach checkout_fast_forward() to use it to fix this regression. After going thourgh all calls to hold_lock*() family of functions that used to pass LOCK_DIE_ON_ERROR but were modified to pass 0 in the "libify sequencer" topic "git show --first-parent 2a4062a4a8", it appears that this is the only one that has become silent. Many others used to give detailed report that talked about "there may be competing Git process running" but with the series merged they now only give a single liner "Unable to lock ...", some of which may have to be tweaked further, but at least they say something, unlike the one this patch fixes. Reported-by: Robbie Iannucci <iannucci@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-12-07 18:56:26 +00:00
if (hold_locked_index(lock_file, LOCK_REPORT_ON_ERROR) < 0)
return -1;
memset(&trees, 0, sizeof(trees));
memset(&opts, 0, sizeof(opts));
memset(&t, 0, sizeof(t));
if (overwrite_ignore) {
memset(&dir, 0, sizeof(dir));
dir.flags |= DIR_SHOW_IGNORED;
setup_standard_excludes(&dir);
opts.dir = &dir;
}
opts.head_idx = 1;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.update = 1;
opts.verbose_update = 1;
opts.merge = 1;
opts.fn = twoway_merge;
setup_unpack_trees_porcelain(&opts, "merge");
trees[nr_trees] = parse_tree_indirect(head);
if (!trees[nr_trees++])
return -1;
trees[nr_trees] = parse_tree_indirect(remote);
if (!trees[nr_trees++])
return -1;
for (i = 0; i < nr_trees; i++) {
parse_tree(trees[i]);
init_tree_desc(t+i, trees[i]->buffer, trees[i]->size);
}
if (unpack_trees(nr_trees, t, &opts))
return -1;
if (write_locked_index(&the_index, lock_file, COMMIT_LOCK)) {
rollback_lock_file(lock_file);
return error(_("unable to write new index file"));
}
return 0;
}