Re: [PATCH 01/15] rebase -i: handle NULL value for rebase.missingCommitsCheck

[Phillip Wood <phillip.wood123@gmail.com>]

Hi Thomas

On 07/11/2026 08:42, Thomas Bachem via GitGitGadget wrote:
> From: Thomas Bachem <mail@thomasbachem.com>
> 
> A rebase.missingCommitsCheck without a value, as in
> 
>    [rebase]
>    missingCommitsCheck
> 
> or "git -c rebase.missingCommitsCheck", makes "git rebase -i"
> segfault as it writes the todo list: get_missing_commit_check_level()
> passes the NULL value to strcasecmp().
> 
> The setting takes "ignore", "warn" or "error", not a bool. Read it
> with repo_config_get_string_tmp(), which rejects a missing value with
> config_error_nonbool(), as ba176db511 (config: handle NULL value when
> parsing non-bools, 2023-12-07) did for other settings.

If the user sets an invalid value for this config option then we print a 
warning and default to "ignore". It would seem reasonable to me to do 
the same for a missing value rather than erroring out.

Thanks for fixing these segfaults

Phillip

> 
> Assisted-by: Claude Fable 5.1
> Signed-off-by: Thomas Bachem <mail@thomasbachem.com>
> ---
>   rebase-interactive.c          | 2 +-
>   t/t3404-rebase-interactive.sh | 7 +++++++
>   2 files changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/rebase-interactive.c b/rebase-interactive.c
> index 809f76a87b..4eb628ee8f 100644
> --- a/rebase-interactive.c
> +++ b/rebase-interactive.c
> @@ -30,7 +30,7 @@ static enum missing_commit_check_level get_missing_commit_check_level(void)
>   {
>   	const char *value;
>   
> -	if (repo_config_get_value(the_repository, "rebase.missingcommitscheck", &value) ||
> +	if (repo_config_get_string_tmp(the_repository, "rebase.missingcommitscheck", &value) ||
>   			!strcasecmp("ignore", value))
>   		return MISSING_COMMIT_CHECK_IGNORE;
>   	if (!strcasecmp("warn", value))
> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
> index ff11abb2f2..813ad2a83d 100755
> --- a/t/t3404-rebase-interactive.sh
> +++ b/t/t3404-rebase-interactive.sh
> @@ -1562,6 +1562,13 @@ test_expect_success 'rebase -i respects rebase.missingCommitsCheck = error' '
>   	test B = $(git cat-file commit HEAD^ | sed -ne \$p)
>   '
>   
> +test_expect_success 'rebase -i rejects rebase.missingCommitsCheck without a value' '
> +	rebase_setup_and_clean missing-commit &&
> +	test_when_finished "test_might_fail git rebase --abort" &&
> +	test_must_fail git -c rebase.missingCommitsCheck rebase -i --root 2>err &&
> +	test_grep "missing value for .rebase.missingcommitscheck." err
> +'
> +
>   test_expect_success 'rebase --edit-todo respects rebase.missingCommitsCheck = ignore' '
>   	test_config rebase.missingCommitsCheck ignore &&
>   	rebase_setup_and_clean missing-commit &&