builtin/fetch: fix leaking transaction with `--atomic`

With the `--atomic` flag, we use a single ref transaction to commit all
ref updates in git-fetch(1). The lifetime of transactions is somewhat
weird: while `ref_transaction_abort()` will free the transaction, a call
to `ref_transaction_commit()` won't. We thus have to manually free the
transaction in the successful case.

Adapt the code to free the transaction in the exit path to plug the
resulting memory leak. As `ref_transaction_abort()` already freed the
transaction for us, we have to unset the transaction when we hit that
code path to not cause a double free.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/fetch.c b/builtin/fetch.c
index c297569a473f133cf7ba8e23f112fd1b0de3fa92..0264483c0e5fc45fa3af7e32834eac408ac5238c 100644 (file)
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -1731,11 +1731,8 @@ static int do_fetch(struct transport *transport,
                        goto cleanup;
 
                retcode = ref_transaction_commit(transaction, &err);
-               if (retcode) {
-                       ref_transaction_free(transaction);
-                       transaction = NULL;
+               if (retcode)
                        goto cleanup;
-               }
        }
 
        commit_fetch_head(&fetch_head);
@@ -1803,8 +1800,11 @@ cleanup:
                if (transaction && ref_transaction_abort(transaction, &err) &&
                    err.len)
                        error("%s", err.buf);
+               transaction = NULL;
        }
 
+       if (transaction)
+               ref_transaction_free(transaction);
        display_state_release(&display_state);
        close_fetch_head(&fetch_head);
        strbuf_release(&err);

diff --git a/t/t5574-fetch-output.sh b/t/t5574-fetch-output.sh
index 5883839a04e991d6ab93a965698662ced064fe3d..f7707326ea158904e86657fe96a99b05c847c535 100755 (executable)
--- a/t/t5574-fetch-output.sh
+++ b/t/t5574-fetch-output.sh
@@ -5,6 +5,7 @@ test_description='git fetch output format'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 test_expect_success 'fetch with invalid output format configuration' '