t4044: update test to work with SHA-256

This test produces pseudo-collisions and tests git diff's behavior with
them, and is therefore sensitive to the hash in use. Update the test to
compute the collisions for both SHA-1 and SHA-256 using appropriate
constants. Move the heredocs inside the setup block so that all of the
setup code can be tested for failure.

Signed-off-by: brian m. carlson <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: bk2204

t/t4044-diff-index-unique-abbrev.sh

@@ -3,34 +3,48 @@
 test_description='test unique sha1 abbreviation on "index from..to" line'
 . ./test-lib.sh
 
-if ! test_have_prereq SHA1
-then
-       skip_all='not using SHA-1 for objects'
-       test_done
-fi
-
-cat >expect_initial <<EOF
-100644 blob 51d2738463ea4ca66f8691c91e33ce64b7d41bb1	foo
-EOF
+test_expect_success 'setup' '
+	test_oid_cache <<-EOF &&
+	val1 sha1:4827
+	val1 sha256:5664
 
-cat >expect_update <<EOF
-100644 blob 51d2738efb4ad8a1e40bed839ab8e116f0a15e47	foo
-EOF
+	val2 sha1:11742
+	val2 sha256:10625
 
-test_expect_success 'setup' '
-	echo 4827 > foo &&
+	hash1 sha1:51d2738463ea4ca66f8691c91e33ce64b7d41bb1
+	hash1 sha256:ae31dfff0af93b2c62b0098a039b38569c43b0a7e97b873000ca42d128f27350
+
+	hasht1 sha1:51d27384
+	hasht1 sha256:ae31dfff
+
+	hash2 sha1:51d2738efb4ad8a1e40bed839ab8e116f0a15e47
+	hash2 sha256:ae31dffada88a46fd5f53c7ed5aa25a7a8951f1d5e88456c317c8d5484d263e5
+
+	hasht2 sha1:51d2738e
+	hasht2 sha256:ae31dffa
+	EOF
+
+	cat >expect_initial <<-EOF &&
+	100644 blob $(test_oid hash1)	foo
+	EOF
+
+	cat >expect_update <<-EOF &&
+	100644 blob $(test_oid hash2)	foo
+	EOF
+
+	echo "$(test_oid val1)" > foo &&
 	git add foo &&
 	git commit -m "initial" &&
 	git cat-file -p HEAD: > actual &&
 	test_cmp expect_initial actual &&
-	echo 11742 > foo &&
+	echo "$(test_oid val2)" > foo &&
 	git commit -a -m "update" &&
 	git cat-file -p HEAD: > actual &&
 	test_cmp expect_update actual
 '
 
 cat >expect <<EOF
-index 51d27384..51d2738e 100644
+index $(test_oid hasht1)..$(test_oid hasht2) 100644
 EOF
 
 test_expect_success 'diff does not produce ambiguous index line' '