t5510: refactor bundle->pack conversion

It's not so much a conversion as a "strip everything up to and
including the first blank line", but it will come in handy again.

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: trast

t/t5510-fetch.sh

@@ -14,6 +14,14 @@ test_bundle_object_count () {
 	test "$2" = $(grep '^[0-9a-f]\{40\} ' verify.out | wc -l)
 }
 
+convert_bundle_to_pack () {
+	while read x && test -n "$x"
+	do
+		:;
+	done
+	cat
+}
+
 test_expect_success setup '
 	echo >file original &&
 	git add file &&
@@ -207,13 +215,7 @@ test_expect_success 'unbundle 1' '
 
 test_expect_success 'bundle 1 has only 3 files ' '
 	cd "$D" &&
-	(
-		while read x && test -n "$x"
-		do
-			:;
-		done
-		cat
-	) <bundle1 >bundle.pack &&
+	convert_bundle_to_pack <bundle1 >bundle.pack &&
 	git index-pack bundle.pack &&
 	test_bundle_object_count bundle.pack 3
 '
@@ -230,13 +232,7 @@ test_expect_success 'bundle does not prerequisite objects' '
 	git add file2 &&
 	git commit -m add.file2 file2 &&
 	git bundle create bundle3 -1 HEAD &&
-	(
-		while read x && test -n "$x"
-		do
-			:;
-		done
-		cat
-	) <bundle3 >bundle.pack &&
+	convert_bundle_to_pack <bundle3 >bundle.pack &&
 	git index-pack bundle.pack &&
 	test_bundle_object_count bundle.pack 3
 '