#!/bin/sh
#
# This test covers the handling of objects which might have old
# mtimes in the filesystem (because they were used previously)
# and are just now becoming referenced again.
#
# We're going to do two things that are a little bit "fake" to
# help make our simulation easier:
#
#   1. We'll turn off reflogs. You can still run into
#      problems with reflogs on, but your objects
#      don't get pruned until both the reflog expiration
#      has passed on their references, _and_ they are out
#      of prune's expiration period. Dropping reflogs
#      means we only have to deal with one variable in our tests,
#      but the results generalize.
#
#   2. We'll use a temporary index file to create our
#      works-in-progress. Most workflows would mention
#      referenced objects in the index, which prune takes
#      into account. However, many operations don't. For
#      example, a partial commit with "git commit foo"
#      will use a temporary index. Or they may not need
#      an index at all (e.g., creating a new commit
#      to refer to an existing tree).

test_description='check pruning of dependent objects'
. ./test-lib.sh

# We care about reachability, so we do not want to use
# the normal test_commit, which creates extra tags.
add () {
        echo "$1" >"$1" &&
        git add "$1"
}
commit () {
        test_tick &&
        add "$1" &&
        git commit -m "$1"
}

maybe_repack () {
        if test -n "$repack"; then
                git repack -ad
        fi
}

for repack in '' true; do
        title=${repack:+repack}
        title=${title:-loose}

        test_expect_success "make repo completely empty ($title)" '
                rm -rf .git &&
                git init
        '

        test_expect_success "disable reflogs ($title)" '
                git config core.logallrefupdates false &&
                git reflog expire --expire=all --all
        '

        test_expect_success "setup basic history ($title)" '
                commit base
        '

        test_expect_success "create and abandon some objects ($title)" '
                git checkout -b experiment &&
                commit abandon &&
                maybe_repack &&
                git checkout master &&
                git branch -D experiment
        '

        test_expect_success "simulate time passing ($title)" '
                find .git/objects -type f |
                xargs test-tool chmtime -v -86400
        '

        test_expect_success "start writing new commit with old blob ($title)" '
                tree=$(
                        GIT_INDEX_FILE=index.tmp &&
                        export GIT_INDEX_FILE &&
                        git read-tree HEAD &&
                        add unrelated &&
                        add abandon &&
                        git write-tree
                )
        '

        test_expect_success "simultaneous gc ($title)" '
                git gc --prune=12.hours.ago
        '

        test_expect_success "finish writing out commit ($title)" '
                commit=$(echo foo | git commit-tree -p HEAD $tree) &&
                git update-ref HEAD $commit
        '

        # "abandon" blob should have been rescued by reference from new tree
        test_expect_success "repository passes fsck ($title)" '
                git fsck
        '

        test_expect_success "abandon objects again ($title)" '
                git reset --hard HEAD^ &&
                find .git/objects -type f |
                xargs test-tool chmtime -v -86400
        '

        test_expect_success "start writing new commit with same tree ($title)" '
                tree=$(
                        GIT_INDEX_FILE=index.tmp &&
                        export GIT_INDEX_FILE &&
                        git read-tree HEAD &&
                        add abandon &&
                        add unrelated &&
                        git write-tree
                )
        '

        test_expect_success "simultaneous gc ($title)" '
                git gc --prune=12.hours.ago
        '

        # tree should have been refreshed by write-tree
        test_expect_success "finish writing out commit ($title)" '
                commit=$(echo foo | git commit-tree -p HEAD $tree) &&
                git update-ref HEAD $commit
        '
done

test_expect_success 'do not complain about existing broken links (commit)' '
        cat >broken-commit <<-\EOF &&
        tree 0000000000000000000000000000000000000001
        parent 0000000000000000000000000000000000000002
        author whatever <whatever@example.com> 1234 -0000
        committer whatever <whatever@example.com> 1234 -0000

        some message
        EOF
        commit=$(git hash-object -t commit -w broken-commit) &&
        git gc 2>stderr &&
        verbose git cat-file -e $commit &&
        test_must_be_empty stderr
'

test_expect_success 'do not complain about existing broken links (tree)' '
        cat >broken-tree <<-\EOF &&
        100644 blob 0000000000000000000000000000000000000003    foo
        EOF
        tree=$(git mktree --missing <broken-tree) &&
        git gc 2>stderr &&
        git cat-file -e $tree &&
        test_must_be_empty stderr
'

test_expect_success 'do not complain about existing broken links (tag)' '
        cat >broken-tag <<-\EOF &&
        object 0000000000000000000000000000000000000004
        type commit
        tag broken
        tagger whatever <whatever@example.com> 1234 -0000

        this is a broken tag
        EOF
        tag=$(git hash-object -t tag -w broken-tag) &&
        git gc 2>stderr &&
        git cat-file -e $tag &&
        test_must_be_empty stderr
'

test_done