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
+'
+
+cat >expect <<\EOF
+error: The following untracked working tree files would be overwritten by merge:
+ sub
+ sub2
+Please move or remove them before you can merge.
+EOF
+
+test_expect_success 'will not overwrite untracked file in leading path' '
+ git reset --hard c0 &&
+ rm -rf sub &&
+ cp important sub &&
+ cp important sub2 &&
+ test_must_fail git merge sub 2>out &&
+ test_cmp out expect &&
+ test_path_is_missing .git/MERGE_HEAD &&
+ test_cmp important sub &&
+ test_cmp important sub2 &&
+ rm -f sub sub2
+'
+
+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
+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_expect_success 'set up unborn branch and content' '
+ git symbolic-ref HEAD refs/heads/unborn &&
+ rm -f .git/index &&
+ echo foo > tracked-file &&
+ git add tracked-file &&
+ echo bar > untracked-file
+ '
+
+ test_expect_failure 'will not clobber WT/index when merging into unborn' '
+ git merge master &&
+ grep foo tracked-file &&
+ git show :tracked-file >expect &&
+ grep foo expect &&
+ grep bar untracked-file
+ '
+
test_done