rebase: use child_process_clear() to clean

In the run_am() function, we set up a child_process struct to run
"git-am", allocating memory for its args and env strvecs. These are
normally cleaned up when we call run_command(). But if we encounter
certain errors, we exit the function early and try to clean up ourselves
by clearing the am.args field. This leaks the "env" strvec.

We should use child_process_clear() instead, which covers both. And more
importantly, it future proofs us against the struct ever growing more
allocated fields.

These are unlikely errors to happen in practice, so they don't actually
trigger the leak sanitizer in the tests. But we can add a new test which
does exercise one of the paths (and fails SANITIZE=leak without this
patch).

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

diff --git a/builtin/rebase.c b/builtin/rebase.c
index 6635f10d5294d16d017eae225de799efb7b1b9aa..acd083bec3e3a97f0715f6d8d49ed203ff2840e5 100644 (file)
--- a/builtin/rebase.c
+++ b/builtin/rebase.c
@@ -653,7 +653,7 @@ static int run_am(struct rebase_options *opts)
                status = error_errno(_("could not open '%s' for writing"),
                                     rebased_patches);
                free(rebased_patches);
-               strvec_clear(&am.args);
+               child_process_clear(&am);
                return status;
        }
 
@@ -676,7 +676,7 @@ static int run_am(struct rebase_options *opts)
                struct reset_head_opts ropts = { 0 };
                unlink(rebased_patches);
                free(rebased_patches);
-               strvec_clear(&am.args);
+               child_process_clear(&am);
 
                ropts.oid = &opts->orig_head->object.oid;
                ropts.branch = opts->head_name;
@@ -699,7 +699,7 @@ static int run_am(struct rebase_options *opts)
                status = error_errno(_("could not open '%s' for reading"),
                                     rebased_patches);
                free(rebased_patches);
-               strvec_clear(&am.args);
+               child_process_clear(&am);
                return status;
        }
 

diff --git a/t/t3438-rebase-broken-files.sh b/t/t3438-rebase-broken-files.sh
index c614c4f2e4ba285ba7ffc6b7b4384b69f0b9a851..821f08e5afb6983cf8f69abc525a54b6274885e6 100755 (executable)
--- a/t/t3438-rebase-broken-files.sh
+++ b/t/t3438-rebase-broken-files.sh
@@ -58,4 +58,13 @@ test_expect_success 'unknown key in author-script' '
        check_resolve_fails
 '
 
+test_expect_success POSIXPERM,SANITY 'unwritable rebased-patches does not leak' '
+       >.git/rebased-patches &&
+       chmod a-w .git/rebased-patches &&
+
+       git checkout -b side HEAD^ &&
+       test_commit unrelated &&
+       test_must_fail git rebase --apply --onto tmp HEAD^
+'
+
 test_done