tests: stop using top-level "README" and "COPYING" files

In 459b8d22e5 (tests: do not borrow from COPYING and README from the
real source, 2015-02-15) tests that used "lib-diff.sh" (called
"diff-lib.sh" then) were made to stop relying on the top-level COPYING
file, but we still had other tests that referenced it.

Let's move them over to use the "COPYING_test_data" utility function
introduced in the preceding commit, and in the case of the one test
that needed the "README" file use a ROT 13 version of that "COPYING"
test data. That test added in afd222967c (Extend testing git-mv for
renaming of subdirectories, 2006-07-26) just needs more test data that's not the same as the "COPYING" test data, so a ROT 13 version will do.

This change removes the last references to ../{README,COPYING} in the
test suite.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t4022-diff-rewrite.sh

@@ -3,15 +3,17 @@
 test_description='rewrite diff'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-diff-data.sh
 
 test_expect_success setup '
 
-	cat "$TEST_DIRECTORY"/../COPYING >test &&
+	COPYING_test_data >test.data &&
+	cp test.data test &&
 	git add test &&
 	tr \
 	  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" \
 	  "nopqrstuvwxyzabcdefghijklmNOPQRSTUVWXYZABCDEFGHIJKLM" \
-	  <"$TEST_DIRECTORY"/../COPYING >test &&
+	  <test.data >test &&
 	echo "to be deleted" >test2 &&
 	blob=$(git hash-object test2) &&
 	blob=$(git rev-parse --short $blob) &&

t/t4023-diff-rename-typechange.sh

@@ -3,25 +3,26 @@
 test_description='typechange rename detection'
 
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-diff.sh
 
 test_expect_success setup '
 
 	rm -f foo bar &&
-	cat "$TEST_DIRECTORY"/../COPYING >foo &&
+	COPYING_test_data >foo &&
 	test_ln_s_add linklink bar &&
 	git add foo &&
 	git commit -a -m Initial &&
 	git tag one &&
 
 	git rm -f foo bar &&
-	cat "$TEST_DIRECTORY"/../COPYING >bar &&
+	COPYING_test_data >bar &&
 	test_ln_s_add linklink foo &&
 	git add bar &&
 	git commit -a -m Second &&
 	git tag two &&
 
 	git rm -f foo bar &&
-	cat "$TEST_DIRECTORY"/../COPYING >foo &&
+	COPYING_test_data >foo &&
 	git add foo &&
 	git commit -a -m Third &&
 	git tag three &&
@@ -35,7 +36,7 @@ test_expect_success setup '
 	# This is purely for sanity check
 
 	git rm -f foo bar &&
-	cat "$TEST_DIRECTORY"/../COPYING >foo &&
+	COPYING_test_data >foo &&
 	cat "$TEST_DIRECTORY"/../Makefile >bar &&
 	git add foo bar &&
 	git commit -a -m Fifth &&
@@ -43,7 +44,7 @@ test_expect_success setup '
 
 	git rm -f foo bar &&
 	cat "$TEST_DIRECTORY"/../Makefile >foo &&
-	cat "$TEST_DIRECTORY"/../COPYING >bar &&
+	COPYING_test_data >bar &&
 	git add foo bar &&
 	git commit -a -m Sixth &&
 	git tag six

t/t7001-mv.sh

@@ -2,10 +2,11 @@
 
 test_description='git mv in subdirs'
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-diff-data.sh
 
 test_expect_success 'prepare reference tree' '
 	mkdir path0 path1 &&
-	cp "$TEST_DIRECTORY"/../COPYING path0/COPYING &&
+	COPYING_test_data >path0/COPYING &&
 	git add path0/COPYING &&
 	git commit -m add -a
 '
@@ -107,7 +108,7 @@ test_expect_success 'clean up' '
 '
 
 test_expect_success 'adding another file' '
-	cp "$TEST_DIRECTORY"/../README.md path0/README &&
+	COPYING_test_data | tr A-Za-z N-ZA-Mn-za-m >path0/README &&
 	git add path0/README &&
 	git commit -m add2 -a
 '

t/t7101-reset-empty-subdirs.sh

@@ -5,10 +5,11 @@
 
 test_description='git reset should cull empty subdirs'
 . ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-diff-data.sh
 
 test_expect_success 'creating initial files' '
      mkdir path0 &&
-     cp "$TEST_DIRECTORY"/../COPYING path0/COPYING &&
+     COPYING_test_data >path0/COPYING &&
      git add path0/COPYING &&
      git commit -m add -a
 '
@@ -16,10 +17,10 @@ test_expect_success 'creating initial files' '
 test_expect_success 'creating second files' '
      mkdir path1 &&
      mkdir path1/path2 &&
-     cp "$TEST_DIRECTORY"/../COPYING path1/path2/COPYING &&
-     cp "$TEST_DIRECTORY"/../COPYING path1/COPYING &&
-     cp "$TEST_DIRECTORY"/../COPYING COPYING &&
-     cp "$TEST_DIRECTORY"/../COPYING path0/COPYING-TOO &&
+     COPYING_test_data >path1/path2/COPYING &&
+     COPYING_test_data >path1/COPYING &&
+     COPYING_test_data >COPYING &&
+     COPYING_test_data >path0/COPYING-TOO &&
      git add path1/path2/COPYING &&
      git add path1/COPYING &&
      git add COPYING &&