test_commit c1a c1.c "c1 a" &&
git reset --hard c0 &&
test_commit c2 c2.c &&
+ git reset --hard c0 &&
+ mkdir sub &&
+ echo "sub/f" > sub/f &&
+ git add sub/f &&
+ git commit -m sub &&
+ git tag sub &&
echo "VERY IMPORTANT CHANGES" > important
'
test_cmp important c2.c
'
+test_expect_success 'will overwrite tracked file' '
+ git reset --hard c1 &&
+ cp important c2.c &&
+ git add c2.c &&
+ git commit -m important &&
+ git checkout c2
+'
+
test_expect_success 'will not overwrite new file' '
git reset --hard c1 &&
cp important c2.c &&
test_cmp important c1.c
'
+test_expect_success 'will not overwrite untracked subtree' '
+ git reset --hard c0 &&
+ rm -rf sub &&
+ mkdir -p sub/f &&
+ cp important sub/f/important &&
+ test_must_fail git merge sub &&
+ test_path_is_missing .git/MERGE_HEAD &&
+ test_cmp important sub/f/important
+'
+
+test_expect_failure 'will not overwrite untracked file in leading path' '
+ git reset --hard c0 &&
+ rm -rf sub &&
+ cp important sub &&
+ test_must_fail git merge sub &&
+ test_path_is_missing .git/MERGE_HEAD &&
+ test_cmp important sub
+'
+
+test_expect_failure SYMLINKS 'will not overwrite untracked symlink in leading path' '
+ git reset --hard c0 &&
+ rm -rf sub &&
+ mkdir sub2 &&
+ ln -s sub2 sub &&
+ test_must_fail git merge sub &&
+ test_path_is_missing .git/MERGE_HEAD
+'
+
+test_expect_success SYMLINKS 'will not be confused by symlink in leading path' '
+ git reset --hard c0 &&
+ rm -rf sub &&
+ ln -s sub2 sub &&
+ git add sub &&
+ git commit -m ln &&
+ git checkout sub
+'
+
cat >expect <<\EOF
error: Untracked working tree file 'c0.c' would be overwritten by merge.
fatal: read-tree failed