@matheusbsbs / matheus-bagliano / commits / e6f8861bd4

setup: introduce startup_info->original_cwd

Removing the current working directory causes all subsequent git commands run from that directory to get confused and fail with a message about being unable to read the current working directory: $ git status fatal: Unable to read current working directory: No such file or directory Non-git commands likely have similar warnings or even errors, e.g. $ bash -c 'echo hello' shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory hello This confuses end users, particularly since the command they get the error from is not the one that caused the problem; the problem came from the side-effect of some previous command. We would like to avoid removing the current working directory of our parent process; towards this end, introduce a new variable, startup_info->original_cwd, that tracks the current working directory that we inherited from our parent process. For convenience of later comparisons, we prefer that this new variable store a path relative to the toplevel working directory (thus much like 'prefix'), except without the trailing slash. Subsequent commits will make use of this new variable. Acked-by: Derrick Stolee <stolee@gmail.com> Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Elijah Newren committed Dec 9, 2021 at 05:08 UTC e6f8861bd43636b27651150e6a3caa0a937fb418

3 files changed +71

cache.h

@@ -1834,8 +1834,10 @@ void overlay_tree_on_index(struct index_state *istate,

1834 struct startup_info {

1835 int have_repository;

1836 const char *prefix;

1837 + const char *original_cwd;

1838 };

1839 extern struct startup_info *startup_info;

1840 +extern const char *tmp_original_cwd;

1841

1842 /* merge.c */

1843 struct commit_list;

common-main.c

@@ -26,6 +26,7 @@ static void restore_sigpipe_to_default(void)

26 int main(int argc, const char **argv)

27 {

28 int result;

29 + struct strbuf tmp = STRBUF_INIT;

31 trace2_initialize_clock();

@@ -49,6 +50,9 @@ int main(int argc, const char **argv)

50 trace2_cmd_start(argv);

51 trace2_collect_process_info(TRACE2_PROCESS_INFO_STARTUP);

53 + if (!strbuf_getcwd(&tmp))

54 + tmp_original_cwd = strbuf_detach(&tmp, NULL);

55 +

56 result = cmd_main(argc, argv);

58 trace2_cmd_exit(result);

setup.c

+65

@@ -12,6 +12,7 @@ static int work_tree_config_is_bogus;

13 static struct startup_info the_startup_info;

14 struct startup_info *startup_info = &the_startup_info;

15 +const char *tmp_original_cwd;

17 /*

18 * The input parameter must contain an absolute path, and it must already be

@@ -432,6 +433,69 @@ void setup_work_tree(void)

433 initialized = 1;

434 }

435

436 +static void setup_original_cwd(void)

437 +{

438 + struct strbuf tmp = STRBUF_INIT;

439 + const char *worktree = NULL;

440 + int offset = -1;

441 +

442 + if (!tmp_original_cwd)

443 + return;

444 +

445 + /*

446 + * startup_info->original_cwd points to the current working

447 + * directory we inherited from our parent process, which is a

448 + * directory we want to avoid removing.

449 + *

450 + * For convience, we would like to have the path relative to the

451 + * worktree instead of an absolute path.

452 + *

453 + * Yes, startup_info->original_cwd is usually the same as 'prefix',

454 + * but differs in two ways:

455 + * - prefix has a trailing '/'

456 + * - if the user passes '-C' to git, that modifies the prefix but

457 + * not startup_info->original_cwd.

458 + */

459 +

460 + /* Normalize the directory */

461 + strbuf_realpath(&tmp, tmp_original_cwd, 1);

462 + free((char*)tmp_original_cwd);

463 + tmp_original_cwd = NULL;

464 + startup_info->original_cwd = strbuf_detach(&tmp, NULL);

465 +

466 + /*

467 + * Get our worktree; we only protect the current working directory

468 + * if it's in the worktree.

469 + */

470 + worktree = get_git_work_tree();

471 + if (!worktree)

472 + goto no_prevention_needed;

473 +

474 + offset = dir_inside_of(startup_info->original_cwd, worktree);

475 + if (offset >= 0) {

476 + /*

477 + * If startup_info->original_cwd == worktree, that is already

478 + * protected and we don't need original_cwd as a secondary

479 + * protection measure.

480 + */

481 + if (!*(startup_info->original_cwd + offset))

482 + goto no_prevention_needed;

483 +

484 + /*

485 + * original_cwd was inside worktree; precompose it just as

486 + * we do prefix so that built up paths will match

487 + */

488 + startup_info->original_cwd = \

489 + precompose_string_if_needed(startup_info->original_cwd

490 + + offset);

491 + return;

492 + }

493 +

494 +no_prevention_needed:

495 + free((char*)startup_info->original_cwd);

496 + startup_info->original_cwd = NULL;

497 +}

498 +

499 static int read_worktree_config(const char *var, const char *value, void *vdata)

500 {

501 struct repository_format *data = vdata;

@@ -1330,6 +1394,7 @@ const char *setup_git_directory_gently(int *nongit_ok)

1394 setenv(GIT_PREFIX_ENVIRONMENT, "", 1);

1395 }

1396

1397 + setup_original_cwd();

1398

1399 strbuf_release(&dir);

1400 strbuf_release(&gitdir);