On 11/12/2018 9:46 AM, Jeff King wrote:
The run-command API makes no promises about what is left in a struct
child_process after a command finishes, and it's not safe to simply
reuse it again for a similar command. In particular:
- if you use child->args or child->env_array, they are cleared after
finish_command()
- likewise, start_command() may point child->argv at child->args->argv;
reusing that would lead to accessing freed memory
- the in/out/err may hold pipe descriptors from the previous run
Thanks! This is helpful information.
These two calls are _probably_ OK because they do not use any of those
features. But it's only by chance, and may break in the future; let's
reinitialize our struct for each program we run.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
builtin/fsck.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/builtin/fsck.c b/builtin/fsck.c
index 06eb421720..b10f2b154c 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -841,6 +841,9 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
prepare_alt_odb(the_repository);
for (alt = the_repository->objects->alt_odb_list; alt; alt = alt->next) {
+ child_process_init(&commit_graph_verify);
+ commit_graph_verify.argv = verify_argv;
+ commit_graph_verify.git_cmd = 1;
verify_argv[2] = "--object-dir";
verify_argv[3] = alt->path;
if (run_command(&commit_graph_verify))
@@ -859,6 +862,9 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
prepare_alt_odb(the_repository);
for (alt = the_repository->objects->alt_odb_list; alt; alt = alt->next) {
+ child_process_init(&midx_verify);
+ midx_verify.argv = midx_argv;
+ midx_verify.git_cmd = 1;
midx_argv[2] = "--object-dir";
midx_argv[3] = alt->path;
if (run_command(&midx_verify))
Looks good to me.
-Stolee
