#!/bin/sh

test_description='git-merge

Do not overwrite changes.'

. ./test-lib.sh

test_expect_success 'setup' '
        echo c0 > c0.c &&
        git add c0.c &&
        git commit -m c0 &&
        git tag c0 &&
        echo c1 > c1.c &&
        git add c1.c &&
        git commit -m c1 &&
        git tag c1 &&
        git reset --hard c0 &&
        echo c2 > c2.c &&
        git add c2.c &&
        git commit -m c2 &&
        git tag c2 &&
        git reset --hard c1 &&
        echo "c1 a" > c1.c &&
        git add c1.c &&
        git commit -m "c1 a" &&
        git tag c1a &&
        echo "VERY IMPORTANT CHANGES" > important
'

test_expect_success 'will not overwrite untracked file' '
        git reset --hard c1 &&
        cat important > c2.c &&
        test_must_fail git merge c2 &&
        test_cmp important c2.c
'

test_expect_success 'will not overwrite new file' '
        git reset --hard c1 &&
        cat important > c2.c &&
        git add c2.c &&
        test_must_fail git merge c2 &&
        test_cmp important c2.c
'

test_expect_success 'will not overwrite staged changes' '
        git reset --hard c1 &&
        cat important > c2.c &&
        git add c2.c &&
        rm c2.c &&
        test_must_fail git merge c2 &&
        git checkout c2.c &&
        test_cmp important c2.c
'

test_expect_success 'will not overwrite removed file' '
        git reset --hard c1 &&
        git rm c1.c &&
        git commit -m "rm c1.c" &&
        cat important > c1.c &&
        test_must_fail git merge c1a &&
        test_cmp important c1.c
'

test_expect_success 'will not overwrite re-added file' '
        git reset --hard c1 &&
        git rm c1.c &&
        git commit -m "rm c1.c" &&
        cat important > c1.c &&
        git add c1.c &&
        test_must_fail git merge c1a &&
        test_cmp important c1.c
'

test_expect_success 'will not overwrite removed file with staged changes' '
        git reset --hard c1 &&
        git rm c1.c &&
        git commit -m "rm c1.c" &&
        cat important > c1.c &&
        git add c1.c &&
        rm c1.c &&
        test_must_fail git merge c1a &&
        git checkout c1.c &&
        test_cmp important c1.c
'

cat >expect <<\EOF
error: Untracked working tree file 'c0.c' would be overwritten by merge.
fatal: read-tree failed
EOF

test_expect_success 'will not overwrite untracked file on unborn branch' '
        git reset --hard c0 &&
        git rm -fr . &&
        git checkout --orphan new &&
        cp important c0.c &&
        test_must_fail git merge c0 2>out &&
        test_cmp out expect &&
        test_path_is_missing .git/MERGE_HEAD &&
        test_cmp important c0.c
'

test_done