sparse-checkout: fix OOM error with mixed patterns

Add a test to t1091-sparse-checkout-builtin.sh that would result in an
infinite loop and out-of-memory error before this change. The issue
relies on having non-cone-mode patterns while trying to modify the
patterns in cone-mode.

The fix is simple, allowing us to break from the loop when the input
path does not contain a slash, as the "dir" pattern we added does not.

This is only a fix to the critical out-of-memory error. A better
response to such a strange state will follow in a later change.

Reported-by: Calbabreaker <calbabreaker@gmail.com>
Helped-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index d0f5c4702be69d0c9fade08ffbf5183c5f3dbe7e..9ccdcde9832e93a8cf771cb8565d01d42dc76eed 100644 (file)
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -483,7 +483,7 @@ static void insert_recursive_pattern(struct pattern_list *pl, struct strbuf *pat
                char *oldpattern = e->pattern;
                size_t newlen;
 
-               if (slash == e->pattern)
+               if (!slash || slash == e->pattern)
                        break;
 
                newlen = slash - e->pattern;

diff --git a/t/t1091-sparse-checkout-builtin.sh b/t/t1091-sparse-checkout-builtin.sh
index 3921ea80138bf55cdf51e1a32808dce29b32c15b..1f877ced0c887c51f63c28aa38b3185a9afe80c9 100755 (executable)
--- a/t/t1091-sparse-checkout-builtin.sh
+++ b/t/t1091-sparse-checkout-builtin.sh
@@ -103,6 +103,17 @@ test_expect_success 'clone --sparse' '
        check_files clone a
 '
 
+test_expect_success 'switching to cone mode with non-cone mode patterns' '
+       git init bad-patterns &&
+       (
+               cd bad-patterns &&
+               git sparse-checkout init &&
+               git sparse-checkout add dir &&
+               git config core.sparseCheckoutCone true &&
+               git sparse-checkout add dir
+       )
+'
+
 test_expect_success 'interaction with clone --no-checkout (unborn index)' '
        git clone --no-checkout "file://$(pwd)/repo" clone_no_checkout &&
        git -C clone_no_checkout sparse-checkout init --cone &&