From c990a4c11dd7bb671da1b30e14568ad986621488 Mon Sep 17 00:00:00 2001 From: Eric Sunshine Date: Mon, 6 Jul 2015 13:30:45 -0400 Subject: [PATCH] checkout: fix bug with --to and relative HEAD Given "git checkout --to HEAD~1", the new worktree's HEAD should begin life at the current branch's HEAD~1, however, it actually ends up at HEAD~2. This happens because: 1. git-checkout resolves HEAD~1 2. to satisfy is_git_directory(), prepare_linked_worktree() creates a HEAD for the new worktree with the value of the resolved HEAD~1 3. git-checkout re-invokes itself with the same arguments within the new worktree to populate the worktree 4. the sub git-checkout resolves HEAD~1 relative to its own HEAD, which is the resolved HEAD~1 from the original invocation, resulting unexpectedly and incorrectly in HEAD~2 (relative to the original) Fix this by unconditionally assigning the current worktree's HEAD as the value of the new worktree's HEAD. As a side-effect, this change also eliminates a dependence within prepare_linked_checkout() upon 'struct branch_info'. The plan is to eventually relocate "git checkout --to" functionality to "git worktree add", and worktree.c won't have knowledge of 'struct branch_info', so removal of this dependency is a step toward that goal. Signed-off-by: Eric Sunshine Signed-off-by: Junio C Hamano --- builtin/checkout.c | 16 ++++++++++++---- t/t2025-checkout-to.sh | 10 ++++++++++ 2 files changed, 22 insertions(+), 4 deletions(-) diff --git a/builtin/checkout.c b/builtin/checkout.c index 2079aa4170..5ada22a390 100644 --- a/builtin/checkout.c +++ b/builtin/checkout.c @@ -863,6 +863,7 @@ static int prepare_linked_checkout(const struct checkout_opts *opts, struct stat st; struct child_process cp; int counter = 0, len, ret; + unsigned char rev[20]; if (!new->commit) die(_("no branch specified")); @@ -920,13 +921,20 @@ static int prepare_linked_checkout(const struct checkout_opts *opts, real_path(get_git_common_dir()), name); /* * This is to keep resolve_ref() happy. We need a valid HEAD - * or is_git_directory() will reject the directory. Any valid - * value would do because this value will be ignored and - * replaced at the next (real) checkout. + * or is_git_directory() will reject the directory. Moreover, HEAD + * in the new worktree must resolve to the same value as HEAD in + * the current tree since the command invoked to populate the new + * worktree will be handed the branch/ref specified by the user. + * For instance, if the user asks for the new worktree to be based + * at HEAD~5, then the resolved HEAD~5 in the new worktree must + * match the resolved HEAD~5 in the current tree in order to match + * the user's expectation. */ + if (!resolve_ref_unsafe("HEAD", 0, rev, NULL)) + die(_("unable to resolve HEAD")); strbuf_reset(&sb); strbuf_addf(&sb, "%s/HEAD", sb_repo.buf); - write_file(sb.buf, 1, "%s\n", sha1_to_hex(new->commit->object.sha1)); + write_file(sb.buf, 1, "%s\n", sha1_to_hex(rev)); strbuf_reset(&sb); strbuf_addf(&sb, "%s/commondir", sb_repo.buf); write_file(sb.buf, 1, "../..\n"); diff --git a/t/t2025-checkout-to.sh b/t/t2025-checkout-to.sh index a8d93366f6..0fd731b4bc 100755 --- a/t/t2025-checkout-to.sh +++ b/t/t2025-checkout-to.sh @@ -134,4 +134,14 @@ test_expect_success 'checkout with grafts' ' test_cmp expected actual ' +test_expect_success 'checkout --to from relative HEAD' ' + test_commit a && + test_commit b && + test_commit c && + git rev-parse HEAD~1 >expected && + git checkout --to relhead HEAD~1 && + git -C relhead rev-parse HEAD >actual && + test_cmp expected actual +' + test_done -- 2.11.4.GIT