@matheusbsbs / matheus-bagliano / commits / 5a8ed3fe45

add-patch: classify '@' as a synonym for 'HEAD'

Currently, (restore, checkout, reset) commands correctly take '@' as a synonym for 'HEAD'. However, in patch mode different prompts/messages are given on command line due to patch mode machinery not considering '@' to be a synonym for 'HEAD' due to literal string comparison with the word 'HEAD', and therefore assigning patch_mode_($command)_nothead and triggering reverse mode (-R in diff-index). The NEEDSWORK comment suggested comparing commit objects to get around this. However, doing so would also take a non-checked out branch pointing to the same commit as HEAD, as HEAD. This would cause confusion to the user. Therefore, after parsing '@', replace it with 'HEAD' as reasonably early as possible. This also solves another problem of disparity between 'git checkout HEAD' and 'git checkout @' (latter detaches at the HEAD commit and the former does not). Trade-offs: - Some of the errors would show the revision argument as 'HEAD' when given '@'. This should be fine, as most users who probably use '@' would be aware that it is a shortcut for 'HEAD' and most probably used to use 'HEAD'. There is also relevant documentation in 'gitrevisions' manpage about '@' being the shortcut for 'HEAD'. Also, the simplicity of the solution far outweighs this cost. - Consider '@' as a shortcut for 'HEAD' even if 'refs/heads/@' exists at a different commit. Naming a branch '@' is an obvious foot-gun and many existing commands already take '@' for 'HEAD' even if 'refs/heads/@' exists at a different commit or does not exist at all (e.g. 'git log @', 'git push origin @' etc.). Therefore this is an existing assumption and should not be a problem. Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Phillip Wood <phillip.wood123@gmail.com> Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Ghanshyam Thakkar committed Feb 13, 2024 at 05:35 UTC 5a8ed3fe450caad740b1c236b3f14151f84bed05

7 files changed +65 -43

add-patch.c

-8

@@ -1729,14 +1729,6 @@ int run_add_p(struct repository *r, enum add_p_mode mode,

1729 if (mode == ADD_P_STASH)

1730 s.mode = &patch_mode_stash;

1731 else if (mode == ADD_P_RESET) {

1732 - /*

1733 - * NEEDSWORK: Instead of comparing to the literal "HEAD",

1734 - * compare the commit objects instead so that other ways of

1735 - * saying the same thing (such as "@") are also handled

1736 - * appropriately.

1737 - *

1738 - * This applies to the cases below too.

1739 - */

1732 if (!revision || !strcmp(revision, "HEAD"))

1733 s.mode = &patch_mode_reset_head;

1734 else

builtin/checkout.c

+3 -1

@@ -1224,7 +1224,9 @@ static void setup_new_branch_info_and_source_tree(

1224 struct tree **source_tree = &opts->source_tree;

1225 struct object_id branch_rev;

1226

1227 - new_branch_info->name = xstrdup(arg);

1227 + /* treat '@' as a shortcut for 'HEAD' */

1228 + new_branch_info->name = !strcmp(arg, "@") ? xstrdup("HEAD") :

1229 + xstrdup(arg);

1230 setup_branch_path(new_branch_info);

1231

1232 if (!check_refname_format(new_branch_info->path, 0) &&

builtin/reset.c

+3 -1

@@ -281,7 +281,9 @@ static void parse_args(struct pathspec *pathspec,

281 verify_filename(prefix, argv[0], 1);

282 }

283 }

284 - *rev_ret = rev;

284 +

285 + /* treat '@' as a shortcut for 'HEAD' */

286 + *rev_ret = !strcmp("@", rev) ? "HEAD" : rev;

287

288 parse_pathspec(pathspec, 0,

289 PATHSPEC_PREFER_FULL |

t/t2016-checkout-patch.sh

+26 -20

@@ -38,26 +38,32 @@ test_expect_success 'git checkout -p with staged changes' '

38 verify_state dir/foo index index

39 '

41 -test_expect_success 'git checkout -p HEAD with NO staged changes: abort' '

42 - set_and_save_state dir/foo work head &&

43 - test_write_lines n y n | git checkout -p HEAD &&

44 - verify_saved_state bar &&

45 - verify_saved_state dir/foo

46 -'

47 -

48 -test_expect_success 'git checkout -p HEAD with NO staged changes: apply' '

49 - test_write_lines n y y | git checkout -p HEAD &&

50 - verify_saved_state bar &&

51 - verify_state dir/foo head head

52 -'

53 -

54 -test_expect_success 'git checkout -p HEAD with change already staged' '

55 - set_state dir/foo index index &&

56 - # the third n is to get out in case it mistakenly does not apply

57 - test_write_lines n y n | git checkout -p HEAD &&

58 - verify_saved_state bar &&

59 - verify_state dir/foo head head

60 -'

41 +for opt in "HEAD" "@"

42 +do

43 + test_expect_success "git checkout -p $opt with NO staged changes: abort" '

44 + set_and_save_state dir/foo work head &&

45 + test_write_lines n y n | git checkout -p $opt >output &&

46 + verify_saved_state bar &&

47 + verify_saved_state dir/foo &&

48 + test_grep "Discard" output

49 + '

50 +

51 + test_expect_success "git checkout -p $opt with NO staged changes: apply" '

52 + test_write_lines n y y | git checkout -p $opt >output &&

53 + verify_saved_state bar &&

54 + verify_state dir/foo head head &&

55 + test_grep "Discard" output

56 + '

57 +

58 + test_expect_success "git checkout -p $opt with change already staged" '

59 + set_state dir/foo index index &&

60 + # the third n is to get out in case it mistakenly does not apply

61 + test_write_lines n y n | git checkout -p $opt >output &&

62 + verify_saved_state bar &&

63 + verify_state dir/foo head head &&

64 + test_grep "Discard" output

65 + '

66 +done

68 test_expect_success 'git checkout -p HEAD^...' '

69 # the third n is to get out in case it mistakenly does not apply

t/t2020-checkout-detach.sh

+12

@@ -45,6 +45,18 @@ test_expect_success 'checkout branch does not detach' '

45 check_not_detached

46 '

48 +for opt in "HEAD" "@"

49 +do

50 + test_expect_success "checkout $opt no-op/don't detach" '

51 + reset &&

52 + cat .git/HEAD >expect &&

53 + git checkout $opt &&

54 + cat .git/HEAD >actual &&

55 + check_not_detached &&

56 + test_cmp expect actual

57 + '

58 +done

59 +

60 test_expect_success 'checkout tag detaches' '

61 reset &&

62 git checkout tag &&

t/t2071-restore-patch.sh

+11 -7

@@ -44,13 +44,17 @@ test_expect_success PERL 'git restore -p with staged changes' '

44 verify_state dir/foo index index

45 '

47 -test_expect_success PERL 'git restore -p --source=HEAD' '

48 - set_state dir/foo work index &&

49 - # the third n is to get out in case it mistakenly does not apply

50 - test_write_lines n y n | git restore -p --source=HEAD &&

51 - verify_saved_state bar &&

52 - verify_state dir/foo head index

53 -'

47 +for opt in "HEAD" "@"

48 +do

49 + test_expect_success PERL "git restore -p --source=$opt" '

50 + set_state dir/foo work index &&

51 + # the third n is to get out in case it mistakenly does not apply

52 + test_write_lines n y n | git restore -p --source=$opt >output &&

53 + verify_saved_state bar &&

54 + verify_state dir/foo head index &&

55 + test_grep "Discard" output

56 + '

57 +done

59 test_expect_success PERL 'git restore -p --source=HEAD^' '

60 set_state dir/foo work index &&

t/t7105-reset-patch.sh

+10 -6

@@ -26,12 +26,16 @@ test_expect_success PERL 'saying "n" does nothing' '

26 verify_saved_state bar

27 '

29 -test_expect_success PERL 'git reset -p' '

30 - test_write_lines n y | git reset -p >output &&

31 - verify_state dir/foo work head &&

32 - verify_saved_state bar &&

33 - test_grep "Unstage" output

34 -'

29 +for opt in "HEAD" "@" ""

30 +do

31 + test_expect_success PERL "git reset -p $opt" '

32 + set_and_save_state dir/foo work work &&

33 + test_write_lines n y | git reset -p $opt >output &&

34 + verify_state dir/foo work head &&

35 + verify_saved_state bar &&

36 + test_grep "Unstage" output

37 + '

38 +done

40 test_expect_success PERL 'git reset -p HEAD^' '

41 test_write_lines n y | git reset -p HEAD^ >output &&