t5304: rename "sha1" variables to "oid"

Let's make the script less jarring to read in a post-sha1 world by
using more hash-agnostic variable names.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: peff

t/t5304-prune.sh

@@ -118,10 +118,10 @@ test_expect_success 'prune: do not prune detached HEAD with no reflog' '
 
 test_expect_success 'prune: prune former HEAD after checking out branch' '
 
-	head_sha1=$(git rev-parse HEAD) &&
+	head_oid=$(git rev-parse HEAD) &&
 	git checkout --quiet master &&
 	git prune -v >prune_actual &&
-	grep "$head_sha1" prune_actual
+	grep "$head_oid" prune_actual
 
 '
 
@@ -265,24 +265,24 @@ EOF
 '
 
 test_expect_success 'prune .git/shallow' '
-	SHA1=$(echo hi|git commit-tree HEAD^{tree}) &&
-	echo $SHA1 >.git/shallow &&
+	oid=$(echo hi|git commit-tree HEAD^{tree}) &&
+	echo $oid >.git/shallow &&
 	git prune --dry-run >out &&
-	grep $SHA1 .git/shallow &&
-	grep $SHA1 out &&
+	grep $oid .git/shallow &&
+	grep $oid out &&
 	git prune &&
 	test_path_is_missing .git/shallow
 '
 
 test_expect_success 'prune .git/shallow when there are no loose objects' '
-	SHA1=$(echo hi|git commit-tree HEAD^{tree}) &&
-	echo $SHA1 >.git/shallow &&
-	git update-ref refs/heads/shallow-tip $SHA1 &&
+	oid=$(echo hi|git commit-tree HEAD^{tree}) &&
+	echo $oid >.git/shallow &&
+	git update-ref refs/heads/shallow-tip $oid &&
 	git repack -ad &&
 	# verify assumption that all loose objects are gone
 	git count-objects | grep ^0 &&
 	git prune &&
-	echo $SHA1 >expect &&
+	echo $oid >expect &&
 	test_cmp expect .git/shallow
 '
 
@@ -326,8 +326,8 @@ test_expect_success 'prune: handle HEAD reflog in multiple worktrees' '
 		git reset --hard HEAD^
 	) &&
 	git prune --expire=now &&
-	SHA1=`git hash-object expected` &&
-	git -C third-worktree show "$SHA1" >actual &&
+	oid=`git hash-object expected` &&
+	git -C third-worktree show "$oid" >actual &&
 	test_cmp expected actual
 '