read-cache.c: clear and free "sparse_checkout_patterns"

The "sparse_checkout_patterns" member was added to the "struct
index_state" in 836e25c (sparse-checkout: hold pattern list in
index, 2021-03-30), but wasn't added to discard_index(). Let's do
that.

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Taylor Blau <[email protected]>

Author: avar

read-cache.c

@@ -2558,6 +2558,11 @@ int discard_index(struct index_state *istate)
 	free_untracked_cache(istate->untracked);
 	istate->untracked = NULL;
 
+	if (istate->sparse_checkout_patterns) {
+		clear_pattern_list(istate->sparse_checkout_patterns);
+		FREE_AND_NULL(istate->sparse_checkout_patterns);
+	}
+
 	if (istate->ce_mem_pool) {
 		mem_pool_discard(istate->ce_mem_pool, should_validate_cache_entries());
 		FREE_AND_NULL(istate->ce_mem_pool);

t/t1011-read-tree-sparse-checkout.sh

@@ -12,6 +12,7 @@ test_description='sparse checkout tests
 '
 
 TEST_CREATE_REPO_NO_TEMPLATE=1
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-read-tree.sh
 

t/t2018-checkout-branch.sh

@@ -3,6 +3,7 @@
 test_description='checkout'
 
 TEST_CREATE_REPO_NO_TEMPLATE=1
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # Arguments: [!] <branch> <oid> [<checkout options>]

t/t6435-merge-sparse.sh

@@ -3,6 +3,7 @@
 test_description='merge with sparse files'
 
 TEST_CREATE_REPO_NO_TEMPLATE=1
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # test_file $filename $content