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@xxxxxxxxx>
Helped-by: Phillip Wood <phillip.wood123@xxxxxxxxx>
Signed-off-by: Ghanshyam Thakkar <shyamthakkar001@xxxxxxxxx>
---
add-patch.c | 8 -------
builtin/checkout.c | 4 +++-
builtin/reset.c | 4 +++-
t/t2016-checkout-patch.sh | 46 +++++++++++++++++++++-----------------
t/t2020-checkout-detach.sh | 12 ++++++++++
t/t2071-restore-patch.sh | 18 +++++++++------
t/t7105-reset-patch.sh | 15 ++++++++-----
7 files changed, 64 insertions(+), 43 deletions(-)
diff --git a/add-patch.c b/add-patch.c
index 79eda168eb..68f525b35c 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -1729,14 +1729,6 @@ int run_add_p(struct repository *r, enum add_p_mode mode,
if (mode == ADD_P_STASH)
s.mode = &patch_mode_stash;
else if (mode == ADD_P_RESET) {
- /*
- * NEEDSWORK: Instead of comparing to the literal "HEAD",
- * compare the commit objects instead so that other ways of
- * saying the same thing (such as "@") are also handled
- * appropriately.
- *
- * This applies to the cases below too.
- */
if (!revision || !strcmp(revision, "HEAD"))
s.mode = &patch_mode_reset_head;
else
diff --git a/builtin/checkout.c b/builtin/checkout.c
index a6e30931b5..067c251933 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1224,7 +1224,9 @@ static void setup_new_branch_info_and_source_tree(
struct tree **source_tree = &opts->source_tree;
struct object_id branch_rev;
- new_branch_info->name = xstrdup(arg);
+ /* treat '@' as a shortcut for 'HEAD' */
+ new_branch_info->name = !strcmp(arg, "@") ? xstrdup("HEAD") :
+ xstrdup(arg);
setup_branch_path(new_branch_info);
if (!check_refname_format(new_branch_info->path, 0) &&
diff --git a/builtin/reset.c b/builtin/reset.c
index 8390bfe4c4..f0bf29a478 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -281,7 +281,9 @@ static void parse_args(struct pathspec *pathspec,
verify_filename(prefix, argv[0], 1);
}
}
- *rev_ret = rev;
+
+ /* treat '@' as a shortcut for 'HEAD' */
+ *rev_ret = !strcmp("@", rev) ? "HEAD" : rev;
parse_pathspec(pathspec, 0,
PATHSPEC_PREFER_FULL |
diff --git a/t/t2016-checkout-patch.sh b/t/t2016-checkout-patch.sh
index 747eb5563e..c4f9bf09aa 100755
--- a/t/t2016-checkout-patch.sh
+++ b/t/t2016-checkout-patch.sh
@@ -38,26 +38,32 @@ test_expect_success 'git checkout -p with staged changes' '
verify_state dir/foo index index
'
-test_expect_success 'git checkout -p HEAD with NO staged changes: abort' '
- set_and_save_state dir/foo work head &&
- test_write_lines n y n | git checkout -p HEAD &&
- verify_saved_state bar &&
- verify_saved_state dir/foo
-'
-
-test_expect_success 'git checkout -p HEAD with NO staged changes: apply' '
- test_write_lines n y y | git checkout -p HEAD &&
- verify_saved_state bar &&
- verify_state dir/foo head head
-'
-
-test_expect_success 'git checkout -p HEAD with change already staged' '
- set_state dir/foo index index &&
- # the third n is to get out in case it mistakenly does not apply
- test_write_lines n y n | git checkout -p HEAD &&
- verify_saved_state bar &&
- verify_state dir/foo head head
-'
+for opt in "HEAD" "@"
+do
+ test_expect_success "git checkout -p $opt with NO staged changes: abort" '
+ set_and_save_state dir/foo work head &&
+ test_write_lines n y n | git checkout -p $opt >output &&
+ verify_saved_state bar &&
+ verify_saved_state dir/foo &&
+ test_grep "Discard" output
+ '
+
+ test_expect_success "git checkout -p $opt with NO staged changes: apply" '
+ test_write_lines n y y | git checkout -p $opt >output &&
+ verify_saved_state bar &&
+ verify_state dir/foo head head &&
+ test_grep "Discard" output
+ '
+
+ test_expect_success "git checkout -p $opt with change already staged" '
+ set_state dir/foo index index &&
+ # the third n is to get out in case it mistakenly does not apply
+ test_write_lines n y n | git checkout -p $opt >output &&
+ verify_saved_state bar &&
+ verify_state dir/foo head head &&
+ test_grep "Discard" output
+ '
+done
test_expect_success 'git checkout -p HEAD^...' '
# the third n is to get out in case it mistakenly does not apply
diff --git a/t/t2020-checkout-detach.sh b/t/t2020-checkout-detach.sh
index 8202ef8c74..bce284c297 100755
--- a/t/t2020-checkout-detach.sh
+++ b/t/t2020-checkout-detach.sh
@@ -45,6 +45,18 @@ test_expect_success 'checkout branch does not detach' '
check_not_detached
'
+for opt in "HEAD" "@"
+do
+ test_expect_success "checkout $opt no-op/don't detach" '
+ reset &&
+ cat .git/HEAD >expect &&
+ git checkout $opt &&
+ cat .git/HEAD >actual &&
+ check_not_detached &&
+ test_cmp expect actual
+ '
+done
+
test_expect_success 'checkout tag detaches' '
reset &&
git checkout tag &&
diff --git a/t/t2071-restore-patch.sh b/t/t2071-restore-patch.sh
index b5c5c0ff7e..3dc9184b4a 100755
--- a/t/t2071-restore-patch.sh
+++ b/t/t2071-restore-patch.sh
@@ -44,13 +44,17 @@ test_expect_success PERL 'git restore -p with staged changes' '
verify_state dir/foo index index
'
-test_expect_success PERL 'git restore -p --source=HEAD' '
- set_state dir/foo work index &&
- # the third n is to get out in case it mistakenly does not apply
- test_write_lines n y n | git restore -p --source=HEAD &&
- verify_saved_state bar &&
- verify_state dir/foo head index
-'
+for opt in "HEAD" "@"
+do
+ test_expect_success PERL "git restore -p --source=$opt" '
+ set_state dir/foo work index &&
+ # the third n is to get out in case it mistakenly does not apply
+ test_write_lines n y n | git restore -p --source=$opt >output &&
+ verify_saved_state bar &&
+ verify_state dir/foo head index &&
+ test_grep "Discard" output
+ '
+done
test_expect_success PERL 'git restore -p --source=HEAD^' '
set_state dir/foo work index &&
diff --git a/t/t7105-reset-patch.sh b/t/t7105-reset-patch.sh
index 05079c7246..0f597416d8 100755
--- a/t/t7105-reset-patch.sh
+++ b/t/t7105-reset-patch.sh
@@ -26,12 +26,15 @@ test_expect_success PERL 'saying "n" does nothing' '
verify_saved_state bar
'
-test_expect_success PERL 'git reset -p' '
- test_write_lines n y | git reset -p >output &&
- verify_state dir/foo work head &&
- verify_saved_state bar &&
- test_grep "Unstage" output
-'
+for opt in "HEAD" "@" ""
+do
+ test_expect_success PERL "git reset -p $opt" '
+ test_write_lines n y | git reset -p $opt >output &&
+ verify_state dir/foo work head &&
+ verify_saved_state bar &&
+ test_grep "Unstage" output
+ '
+done
test_expect_success PERL 'git reset -p HEAD^' '
test_write_lines n y | git reset -p HEAD^ >output &&
--
2.43.0
