Document that "diff --git" criss-cross renames don't work

* NEWS: Document that "diff --git" criss-cross renames are broken
still.
* tests/criss-cross: Test case currently expected to fail.

4 files changed, 54 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 0db1863..40f3785 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -34,6 +34,10 @@
 	generated here.
 	* tests/unmodified-files, tests/copy-rename: Update.
 
+	* NEWS: Document that "diff --git" criss-cross renames are broken
+	still.
+	* tests/criss-cross: Test case currently expected to fail.
+
 2010-07-27  Tim Waugh  <twaugh@redhat.com>
 
 	* src/patch.c: Stops "patch --get 1" from segfaulting.
diff --git a/NEWS b/NEWS
index 6ec1626..f46f12d 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,9 @@
 * Support for most features of the "diff --git" format: renames and copies,
-  permission changes, symlink diffs.  (Binary diffs are not supported yet;
-  patch will complain and skip them.)
+  permission changes, symlink diffs.  Caveats:
+  + Binary diffs are not supported yet; patch will complain and skip them.
+  + In the "diff --git" format, all the patches are relative to the original
+    state of the files to patch, allowing things like criss-cross renames.
+    GNU patch will currently fail for such patches.
 * Support for double-quoted filenames: when a filename in a context diff
   starts with a double quote, it is interpreted as a C string literal.  The
   escape sequences \\, \", \a, \b, \f, \n, \r, \t, \v, and \ooo (a three-digit
diff --git a/tests/Makefile.am b/tests/Makefile.am
index fbade22..ffe02af 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -22,6 +22,7 @@ TESTS = \
 	copy-rename \
 	corrupt-reject-files \
 	create-delete \
+	criss-cross \
 	crlf-handling \
 	dash-o-append \
 	empty-files \
@@ -46,6 +47,7 @@ TESTS = \
 	unmodified-files
 
 XFAIL_TESTS = \
+	criss-cross \
 	dash-o-append
 
 EXTRA_DIST = \
diff --git a/tests/criss-cross b/tests/criss-cross
new file mode 100644
index 0000000..e3ff959
--- /dev/null
+++ b/tests/criss-cross
@@ -0,0 +1,43 @@
+# Copyright (C) 2010 Free Software Foundation, Inc.
+#
+# Copying and distribution of this file, with or without modification,
+# in any medium, are permitted without royalty provided the copyright
+# notice and this notice are preserved.
+
+# git diffs: criss-cross renames
+
+. $srcdir/test-lib.sh
+
+require_cat
+use_local_patch
+use_tmpdir
+
+# ==============================================================
+# Criss-cross rename
+
+echo 1 > f
+echo 2 > g
+
+cat > criss-cross-rename.diff <<EOF
+diff --git a/g b/f
+similarity index 100%
+rename from g
+rename to f
+diff --git a/f b/g
+similarity index 100%
+rename from f
+rename to g
+EOF
+
+check 'patch -p1 < criss-cross-rename.diff || echo "Status: $?"' <<EOF
+patching file f (renamed from g)
+patching file g (renamed from f)
+EOF
+
+check 'cat f' <<EOF
+2
+EOF
+
+check 'cat g' <<EOF
+1
+EOF