p2000: add 'git checkout -' test and decrease depth

As we increase our list of commands to test in
p2000-sparse-operations.sh, we will want to have a slightly smaller test
repository. Reduce the size by a factor of four by reducing the depth of
the step that creates a big index around a moderately-sized repository.

Also add a step to run 'git checkout -' on repeat. This requires having
a previous location in the reflog, so add that to the initialization
steps.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/perf/p2000-sparse-operations.sh

@@ -6,7 +6,7 @@ test_description="test performance of Git operations using the index"
 
 test_perf_default_repo
 
-SPARSE_CONE=f2/f4/f1
+SPARSE_CONE=f2/f4
 
 test_expect_success 'setup repo and indexes' '
 	git reset --hard HEAD &&
@@ -27,7 +27,7 @@ test_expect_success 'setup repo and indexes' '
 	OLD_COMMIT=$(git rev-parse HEAD) &&
 	OLD_TREE=$(git rev-parse HEAD^{tree}) &&
 
-	for i in $(test_seq 1 4)
+	for i in $(test_seq 1 3)
 	do
 		cat >in <<-EOF &&
 			100755 blob $BLOB	a
@@ -43,14 +43,23 @@ test_expect_success 'setup repo and indexes' '
 	done &&
 
 	git sparse-checkout init --cone &&
-	git branch -f wide $OLD_COMMIT &&
+	git sparse-checkout set $SPARSE_CONE &&
+	git checkout -b wide $OLD_COMMIT &&
+
+	for l2 in f1 f2 f3 f4
+	do
+		echo more bogus >>$SPARSE_CONE/$l2/a &&
+		git commit -a -m "edit $SPARSE_CONE/$l2/a" || return 1
+	done &&
+
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-index-v3 &&
 	(
 		cd full-index-v3 &&
 		git sparse-checkout init --cone &&
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 3 &&
-		git update-index --index-version=3
+		git update-index --index-version=3 &&
+		git checkout HEAD~4
 	) &&
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . full-index-v4 &&
 	(
@@ -58,7 +67,8 @@ test_expect_success 'setup repo and indexes' '
 		git sparse-checkout init --cone &&
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 4 &&
-		git update-index --index-version=4
+		git update-index --index-version=4 &&
+		git checkout HEAD~4
 	) &&
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-index-v3 &&
 	(
@@ -66,7 +76,8 @@ test_expect_success 'setup repo and indexes' '
 		git sparse-checkout init --cone --sparse-index &&
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 3 &&
-		git update-index --index-version=3
+		git update-index --index-version=3 &&
+		git checkout HEAD~4
 	) &&
 	git -c core.sparseCheckoutCone=true clone --branch=wide --sparse . sparse-index-v4 &&
 	(
@@ -74,7 +85,8 @@ test_expect_success 'setup repo and indexes' '
 		git sparse-checkout init --cone --sparse-index &&
 		git sparse-checkout set $SPARSE_CONE &&
 		git config index.version 4 &&
-		git update-index --index-version=4
+		git update-index --index-version=4 &&
+		git checkout HEAD~4
 	)
 '
 
@@ -97,5 +109,6 @@ test_perf_on_all git status
 test_perf_on_all git add -A
 test_perf_on_all git add .
 test_perf_on_all git commit -a -m A
+test_perf_on_all git checkout -f -
 
 test_done