From: Phillip Wood Date: Mon, 08 Sep 2025 15:21:38 GMT Subject: Re: [PATCH v2] contrib/subtree: fix split with squashed subtrees Message-ID: In-Reply-To: <20250905022728.940664-1-ask+git@howdoi.land> Hi Colin This is looking good. I've left a few comments below, especially on the new test. On 05/09/2025 03:27, Colin Stagner wrote: > > -# Usage: check if a commit from another subtree should be > +# Usage: should_ignore_subtree_split_commit REV > +# > +# Check if REV is a commit from another subtree and should be > # ignored from processing for splits > should_ignore_subtree_split_commit () { > assert test $# = 1 > - local rev="$1" > + > + git show \ > + --no-patch \ > + --no-show-signature \ > + --format='%(trailers:key=git-subtree-dir,key=git-subtree-mainline)' \ > + "$1" | > + ( > + have_mainline= > + subtree_dir= > + > + while read -r trailer val > + do > + case "$trailer" in > + (git-subtree-dir:) > + subtree_dir="${val%/}" ;; > + (git-subtree-mainline:) > + have_mainline=y ;; > + esac > + done This looks good, we run git log once and then parse the trailers. We do not use the optional '(' in case statements in our code though. > - if test -n "$(git log -1 --grep="git-subtree-dir:" $rev)" > + if test -n "${subtree_dir:-}" && > + test -z "${have_mainline:-}" && > + test "${subtree_dir}" != "$arg_prefix" If we have a git-subtree-dir: trailer whose value does not match the subtree we're interested in and there is no git-subtree-mainline: trailer then we skip this commit - good. What's the idea behind using "${var:-}" rather than "{var}"? > then > - if test -z "$(git log -1 --grep="git-subtree-mainline:" $rev)" && > - test -z "$(git log -1 --grep="git-subtree-dir: $arg_prefix$" $rev)" > - then > - return 0 > - fi > + return 0 > fi > return 1 > + ) > } > > # Usage: process_split_commit REV PARENTS > diff --git a/contrib/subtree/t/t7900-subtree.sh b/contrib/subtree/t/t7900-subtree.sh > index ca4df5be83..8bd45e7be7 100755 > --- a/contrib/subtree/t/t7900-subtree.sh > +++ b/contrib/subtree/t/t7900-subtree.sh > @@ -67,6 +67,34 @@ test_create_pre2_32_repo () { > git -C "$1-clone" replace HEAD^2 $new_commit > } > > +# test_create_subtree_add REPO ORPHAN PREFIX FILENAME ... > +# > +# Create a simple subtree on a new branch named ORPHAN in REPO. > +# The subtree is then merged into the current branch of REPO, > +# under PREFIX. The generated subtree has has one commit > +# with subject and tag FILENAME with a single file "FILENAME.t" > +# > +# When this method returns: > +# - the current branch of REPO will have file PREFIX/FILENAME.t > +# - REPO will have a branch named ORPHAN with subtree history > +# > +# additional arguments are forwarded to "subtree add" > +test_create_subtree_add () { > + ( > + cd "$1" && > + orphan="$2" && > + prefix="$3" && > + filename="$4" && > + shift 4 && > + last="$(git branch --show-current)" && > + git checkout --orphan "$orphan" && > + git rm -rf . && If you use "git switch --orphan" that clears the worktree for you > + test_commit "$filename" && > + git checkout "$last" && I think this could be "git checkout @{-1}" and then we'd avoid having to run "git branch" above > + git subtree add --prefix="$prefix" "$@" "$orphan" > + ) > +} > + > test_expect_success 'shows short help text for -h' ' > test_expect_code 129 git subtree -h >out 2>err && > test_must_be_empty err && > @@ -425,6 +453,48 @@ test_expect_success 'split with multiple subtrees' ' > --squash --rejoin -d -m "Sub B Split 1" 2>&1 | grep -w "\[1\]")" = "" > ' > > +# When subtree split-ing a directory that has other subtree > +# *merges* underneath it, the split must include those subtrees. > +# This test creates a nested subtree, `subA/subB`, and tests > +# that the tree is correct after a subtree split of `subA/`. > +# The test covers: > +# - An initial `subtree add`; and > +# - A follow-up `subtree merge` > +# both with and without `--squashed`. > +for is_squashed in '' 'y'; no need for ';' at the end of the line > +do > + test_expect_success "split keeps nested ${is_squashed:+--squash }subtrees that are part of the split" ' > + subtree_test_create_repo "$test_count" && > + ( > + cd "$test_count" && > + mkdir subA && > + test_commit subA/file1 && > + git branch -m main && For tests that depend on the default branch name you can add GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME to the start of the file before it sources test-lib.sh. Or we could change subtree_create_repo() to pass all its arguments along to test_create_repo() and use "subtree_create_repo --initial-branch=main $test_count" > + test_create_subtree_add \ > + . mksubtree subA/subB file2 ${is_squashed:+--squash} && > + test -e subA/file1.t && We have test_path_is_file() for this which prints a useful diagnostic message it it fails Thanks Phillip > + test -e subA/subB/file2.t && > + git subtree split --prefix=subA --branch=bsplit && > + git checkout bsplit && > + test -e file1.t && > + test -e subB/file2.t && > + git checkout mksubtree && > + git branch -D bsplit && > + test_commit file3 && > + git checkout main && > + git subtree merge \ > + ${is_squashed:+--squash} \ > + --prefix=subA/subB mksubtree && > + test -e subA/subB/file3.t && > + git subtree split --prefix=subA --branch=bsplit && > + git checkout bsplit && > + test -e file1.t && > + test -e subB/file2.t && > + test -e subB/file3.t > + ) > + ' > +done > + > test_expect_success 'split sub dir/ with --rejoin from scratch' ' > subtree_test_create_repo "$test_count" && > test_create_commit "$test_count" main1 && > > base-commit: 09669c729af92144fde84e97d358759b5b42b555