git-commit-vandalism/t/t5572-pull-submodule.sh
Philippe Blain 5176f20ffe pull: check for local submodule modifications with the right range
Ever since 'git pull' learned '--recurse-submodules' in a6d7eb2c7a
(pull: optionally rebase submodules (remote submodule changes only),
2017-06-23), we check if there are local submodule modifications by
checking the revision range 'curr_head --not rebase_fork_point'.

The goal of this check is to abort the pull if there are submodule
modifications in the local commits being rebased, since this scenario is
not supported.

However, the actual range of commits being rebased is not
'rebase_fork_point..curr_head', as the logic in
'get_rebase_newbase_and_upstream' reveals, it is 'upstream..curr_head'.

If the 'git merge-base --fork-point' invocation in
'get_rebase_fork_point' fails to find a fork point between the current
branch and the remote-tracking branch we are pulling from,
'rebase_fork_point' is null and since 4d36f88be7 (submodule: do not pass
null OID to setup_revisions, 2018-05-24), 'submodule_touches_in_range'
checks 'curr_head' and all its ancestors for submodule modifications.

Since it is highly likely that there are submodule modifications in this
range (which is in effect the whole history of the current branch), this
prevents 'git pull --rebase --recurse-submodules' from succeeding if no
fork point exists between the current branch and the remote-tracking
branch being pulled. This can happen, for example, when the current
branch was forked from a commit which was never recorded in the reflog
of the remote-tracking branch we are pulling, as the last two paragraphs
of the "Discussion on fork-point mode" section in git-merge-base(1)
explain.

Fix this bug by passing 'upstream' instead of 'rebase_fork_point' as the
'excl_oid' argument to 'submodule_touches_in_range'.

Reported-by: Brice Goglin <bgoglin@free.fr>
Signed-off-by: Philippe Blain <levraiphilippeblain@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-16 16:01:13 -08:00

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#!/bin/sh
test_description='pull can handle submodules'
. ./test-lib.sh
. "$TEST_DIRECTORY"/lib-submodule-update.sh
reset_branch_to_HEAD () {
git branch -D "$1" &&
git checkout -b "$1" HEAD &&
git branch --set-upstream-to="origin/$1" "$1"
}
git_pull () {
reset_branch_to_HEAD "$1" &&
may_only_be_test_must_fail "$2" &&
$2 git pull
}
# pulls without conflicts
test_submodule_switch_func "git_pull"
git_pull_ff () {
reset_branch_to_HEAD "$1" &&
may_only_be_test_must_fail "$2" &&
$2 git pull --ff
}
test_submodule_switch_func "git_pull_ff"
git_pull_ff_only () {
reset_branch_to_HEAD "$1" &&
may_only_be_test_must_fail "$2" &&
$2 git pull --ff-only
}
test_submodule_switch_func "git_pull_ff_only"
git_pull_noff () {
reset_branch_to_HEAD "$1" &&
may_only_be_test_must_fail "$2" &&
$2 git pull --no-ff
}
KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1
test_submodule_switch_func "git_pull_noff"
test_expect_success 'pull --recurse-submodule setup' '
test_create_repo child &&
test_commit -C child bar &&
test_create_repo parent &&
test_commit -C child foo &&
git -C parent submodule add ../child sub &&
git -C parent commit -m "add submodule" &&
git clone --recurse-submodules parent super
'
test_expect_success 'recursive pull updates working tree' '
test_commit -C child merge_strategy &&
git -C parent submodule update --remote &&
git -C parent add sub &&
git -C parent commit -m "update submodule" &&
git -C super pull --no-rebase --recurse-submodules &&
test_path_is_file super/sub/merge_strategy.t
'
test_expect_success "submodule.recurse option triggers recursive pull" '
test_commit -C child merge_strategy_2 &&
git -C parent submodule update --remote &&
git -C parent add sub &&
git -C parent commit -m "update submodule" &&
git -C super -c submodule.recurse pull --no-rebase &&
test_path_is_file super/sub/merge_strategy_2.t
'
test_expect_success " --[no-]recurse-submodule and submodule.recurse" '
test_commit -C child merge_strategy_3 &&
git -C parent submodule update --remote &&
git -C parent add sub &&
git -C parent commit -m "update submodule" &&
git -C super -c submodule.recurse pull --no-recurse-submodules --no-rebase &&
test_path_is_missing super/sub/merge_strategy_3.t &&
git -C super -c submodule.recurse=false pull --recurse-submodules --no-rebase &&
test_path_is_file super/sub/merge_strategy_3.t &&
test_commit -C child merge_strategy_4 &&
git -C parent submodule update --remote &&
git -C parent add sub &&
git -C parent commit -m "update submodule" &&
git -C super -c submodule.recurse=false pull --no-recurse-submodules --no-rebase &&
test_path_is_missing super/sub/merge_strategy_4.t &&
git -C super -c submodule.recurse=true pull --recurse-submodules --no-rebase &&
test_path_is_file super/sub/merge_strategy_4.t
'
test_expect_success 'pull --rebase --recurse-submodules (remote superproject submodule changes, local submodule changes)' '
# This tests the following scenario :
# - local submodule has new commits
# - local superproject does not have new commits
# - upstream superproject has new commits that change the submodule pointer
# change upstream
test_commit -C child rebase_strategy &&
git -C parent submodule update --remote &&
git -C parent add sub &&
git -C parent commit -m "update submodule" &&
# also have local commits
test_commit -C super/sub local_stuff &&
git -C super pull --rebase --recurse-submodules &&
test_path_is_file super/sub/rebase_strategy.t &&
test_path_is_file super/sub/local_stuff.t
'
test_expect_success 'pull --rebase --recurse-submodules fails if both sides record submodule changes' '
# This tests the following scenario :
# - local superproject has new commits that change the submodule pointer
# - upstream superproject has new commits that change the submodule pointer
# local changes in submodule recorded in superproject:
test_commit -C super/sub local_stuff_2 &&
git -C super add sub &&
git -C super commit -m "local update submodule" &&
# and in the remote as well:
test_commit -C child important_upstream_work &&
git -C parent submodule update --remote &&
git -C parent add sub &&
git -C parent commit -m "remote update submodule" &&
# Unfortunately we fail here, despite no conflict in the
# submodule itself, but the merge strategy in submodules
# does not support rebase:
test_must_fail git -C super pull --rebase --recurse-submodules 2>err &&
test_i18ngrep "locally recorded submodule modifications" err
'
test_expect_success 'pull --rebase --recurse-submodules (no submodule changes, no fork-point)' '
# This tests the following scenario :
# - local submodule does not have new commits
# - local superproject has new commits that *do not* change the submodule pointer
# - upstream superproject has new commits that *do not* change the submodule pointer
# - local superproject branch has no fork-point with its remote-tracking counter-part
# create upstream superproject
test_create_repo submodule &&
test_commit -C submodule first_in_sub &&
test_create_repo superprojet &&
test_commit -C superprojet first_in_super &&
git -C superprojet submodule add ../submodule &&
git -C superprojet commit -m "add submodule" &&
test_commit -C superprojet third_in_super &&
# clone superproject
git clone --recurse-submodules superprojet superclone &&
# add commits upstream
test_commit -C superprojet fourth_in_super &&
# create topic branch in clone, not based on any remote-tracking branch
git -C superclone checkout -b feat HEAD~1 &&
test_commit -C superclone first_on_feat &&
git -C superclone pull --rebase --recurse-submodules origin master
'
# NOTE:
#
# This test is particular because there is only a single commit in the upstream superproject
# 'parent' (which adds the submodule 'a-submodule'). The clone of the superproject
# ('child') hard-resets its branch to a new root commit with the same tree as the one
# from the upstream superproject, so that its branch has no merge-base with its
# remote-tracking counterpart, and then calls 'git pull --recurse-submodules --rebase'.
# The result is that the local branch is reset to the remote-tracking branch (as it was
# originally before the hard-reset).
# The only commit in the range generated by 'submodule.c::submodule_touches_in_range' and
# passed to 'submodule.c::collect_changed_submodules' is the new (regenerated) initial commit,
# which adds the submodule.
# However, 'submodule_touches_in_range' does not error (even though this commit adds the submodule)
# because 'combine-diff.c::diff_tree_combined' returns early, as the initial commit has no parents.
test_expect_success 'branch has no merge base with remote-tracking counterpart' '
rm -rf parent child &&
test_create_repo a-submodule &&
test_commit -C a-submodule foo &&
test_create_repo parent &&
git -C parent submodule add "$(pwd)/a-submodule" &&
git -C parent commit -m foo &&
git clone parent child &&
# Reset master so that it has no merge base with
# refs/remotes/origin/master.
OTHER=$(git -C child commit-tree -m bar \
$(git -C child rev-parse HEAD^{tree})) &&
git -C child reset --hard "$OTHER" &&
git -C child pull --recurse-submodules --rebase
'
test_done