[BUG/PATCH] t9350-fast-export: Add failing test for symlink-to-directory

[Anders Kaseorg <andersk@mit.edu>]

git fast-export | git fast-import fails to preserve a commit that replaces 
a symlink with a directory.  Add a failing test case demonstrating this 
bug.

The fast-export output for the commit in question looks like

  commit refs/heads/master
  mark :4
  author …
  committer …
  data 4
  two
  M 100644 :1 foo/world
  D foo

fast-import deletes the symlink foo and ignores foo/world.  Swapping the M 
line with the D line would give the correct result.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
---
 t/t9350-fast-export.sh | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index 66c8b0a..5fb8a04 100755
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -419,6 +419,30 @@ test_expect_success 'directory becomes symlink'        '
 	(cd result && git show master:foo)
 '
 
+test_expect_failure 'symlink becomes directory'        '
+	git init symlinktodir &&
+	git init symlinktodirresult &&
+	(
+		cd symlinktodir &&
+		mkdir bar &&
+		echo hello > bar/world &&
+		test_ln_s_add bar foo &&
+		git add foo bar/world &&
+		git commit -q -mone &&
+		git rm foo &&
+		mkdir foo &&
+		echo hello > foo/world &&
+		git add foo/world &&
+		git commit -q -mtwo
+	) &&
+	(
+		cd symlinktodir &&
+		git fast-export master -- foo |
+		(cd ../symlinktodirresult && git fast-import --quiet)
+	) &&
+	(cd symlinktodirresult && git show master:foo)
+'
+
 test_expect_success 'fast-export quotes pathnames' '
 	git init crazy-paths &&
 	(cd crazy-paths &&
-- 
2.5.0