t5512: stop losing git exit code in here-docs

The expected references are generated using a here-doc with some inline
command substitutions. If one of the `git rev-parse` invocations within
the command substitutions fails, its return code is swallowed and we
won't know about it. Replace these command substitutions with
generate_references(), which actually reports when `git rev-parse`
fails.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t5512-ls-remote.sh

@@ -4,6 +4,14 @@ test_description='git ls-remote'
 
 . ./test-lib.sh
 
+generate_references () {
+	for ref
+	do
+		oid=$(git rev-parse "$ref") &&
+		printf '%s\t%s\n' "$oid" "$ref" || return 1
+	done
+}
+
 test_expect_success setup '
 	>file &&
 	git add file &&
@@ -43,34 +51,31 @@ test_expect_success 'ls-remote self' '
 '
 
 test_expect_success 'ls-remote --sort="version:refname" --tags self' '
-	cat >expect <<-EOF &&
-	$(git rev-parse mark)	refs/tags/mark
-	$(git rev-parse mark1.1)	refs/tags/mark1.1
-	$(git rev-parse mark1.2)	refs/tags/mark1.2
-	$(git rev-parse mark1.10)	refs/tags/mark1.10
-	EOF
+	generate_references \
+		refs/tags/mark \
+		refs/tags/mark1.1 \
+		refs/tags/mark1.2 \
+		refs/tags/mark1.10 >expect &&
 	git ls-remote --sort="version:refname" --tags self >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'ls-remote --sort="-version:refname" --tags self' '
-	cat >expect <<-EOF &&
-	$(git rev-parse mark1.10)	refs/tags/mark1.10
-	$(git rev-parse mark1.2)	refs/tags/mark1.2
-	$(git rev-parse mark1.1)	refs/tags/mark1.1
-	$(git rev-parse mark)	refs/tags/mark
-	EOF
+	generate_references \
+		refs/tags/mark1.10 \
+		refs/tags/mark1.2 \
+		refs/tags/mark1.1 \
+		refs/tags/mark >expect &&
 	git ls-remote --sort="-version:refname" --tags self >actual &&
 	test_cmp expect actual
 '
 
 test_expect_success 'ls-remote --sort="-refname" --tags self' '
-	cat >expect <<-EOF &&
-	$(git rev-parse mark1.2)	refs/tags/mark1.2
-	$(git rev-parse mark1.10)	refs/tags/mark1.10
-	$(git rev-parse mark1.1)	refs/tags/mark1.1
-	$(git rev-parse mark)	refs/tags/mark
-	EOF
+	generate_references \
+		refs/tags/mark1.2 \
+		refs/tags/mark1.10 \
+		refs/tags/mark1.1 \
+		refs/tags/mark >expect &&
 	git ls-remote --sort="-refname" --tags self >actual &&
 	test_cmp expect actual
 '
@@ -212,17 +217,18 @@ test_expect_success 'protocol v2 supports hiderefs' '
 
 test_expect_success 'ls-remote --symref' '
 	git fetch origin &&
-	cat >expect <<-EOF &&
-	ref: refs/heads/master	HEAD
-	$(git rev-parse HEAD)	HEAD
-	$(git rev-parse refs/heads/master)	refs/heads/master
-	$(git rev-parse HEAD)	refs/remotes/origin/HEAD
-	$(git rev-parse refs/remotes/origin/master)	refs/remotes/origin/master
-	$(git rev-parse refs/tags/mark)	refs/tags/mark
-	$(git rev-parse refs/tags/mark1.1)	refs/tags/mark1.1
-	$(git rev-parse refs/tags/mark1.10)	refs/tags/mark1.10
-	$(git rev-parse refs/tags/mark1.2)	refs/tags/mark1.2
-	EOF
+	echo "ref: refs/heads/master	HEAD" >expect &&
+	generate_references \
+		HEAD \
+		refs/heads/master >>expect &&
+	oid=$(git rev-parse HEAD) &&
+	echo "$oid	refs/remotes/origin/HEAD" >>expect &&
+	generate_references \
+		refs/remotes/origin/master \
+		refs/tags/mark \
+		refs/tags/mark1.1 \
+		refs/tags/mark1.10 \
+		refs/tags/mark1.2 >>expect &&
 	# Protocol v2 supports sending symrefs for refs other than HEAD, so use
 	# protocol v0 here.
 	GIT_TEST_PROTOCOL_VERSION=0 git ls-remote --symref >actual &&