[PATCH 0/2] Fixes for dl/stash-show-untracked

[PATCH 0/2] Fixes for dl/stash-show-untracked

[Denton Liu]

These follow-up patches for the topic should be merged before the
next release happens. In particular, the last patch fixes a potential
segfault that occurs.

Denton Liu (2):
  t3905: correct test title
  stash show: fix segfault with --{include,only}-untracked

 builtin/stash.c                    |  8 ++++++--
 t/t3905-stash-include-untracked.sh | 17 ++++++++++++++++-
 2 files changed, 22 insertions(+), 3 deletions(-)

-- 
2.31.1.751.gd2f1c929bd

[PATCH 1/2] t3905: correct test title

[Denton Liu]

We reference the non-existent option `git stash show --show-untracked`
when we really meant `--only-untracked`. Correct the test title
accordingly.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 t/t3905-stash-include-untracked.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/t/t3905-stash-include-untracked.sh b/t/t3905-stash-include-untracked.sh
index b470db7ef7..2e6796725b 100755
--- a/t/t3905-stash-include-untracked.sh
+++ b/t/t3905-stash-include-untracked.sh
@@ -367,7 +367,7 @@ test_expect_success 'stash show --only-untracked only shows untracked files' '
 	test_cmp expect actual
 '
 
-test_expect_success 'stash show --no-include-untracked cancels --{include,show}-untracked' '
+test_expect_success 'stash show --no-include-untracked cancels --{include,only}-untracked' '
 	git reset --hard &&
 	git clean -xf &&
 	>untracked &&
-- 
2.31.1.751.gd2f1c929bd

[PATCH 2/2] stash show: fix segfault with --{include,only}-untracked

[Denton Liu]

When `git stash show --include-untracked` or
`git stash show --only-untracked` is run on a stash that doesn't include
an untracked entry, a segfault occurs. This happens because we do not
check whether the untracked entry is actually present and just attempt
to blindly dereference it.

Ensure that the untracked entry is present before actually attempting to
dereference it.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 builtin/stash.c                    |  8 ++++++--
 t/t3905-stash-include-untracked.sh | 15 +++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/builtin/stash.c b/builtin/stash.c
index 8922a1240c..82e4829d44 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -900,10 +900,14 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 		diff_tree_oid(&info.b_commit, &info.w_commit, "", &rev.diffopt);
 		break;
 	case UNTRACKED_ONLY:
-		diff_root_tree_oid(&info.u_tree, "", &rev.diffopt);
+		if (info.has_u)
+			diff_root_tree_oid(&info.u_tree, "", &rev.diffopt);
 		break;
 	case UNTRACKED_INCLUDE:
-		diff_include_untracked(&info, &rev.diffopt);
+		if (info.has_u)
+			diff_include_untracked(&info, &rev.diffopt);
+		else
+			diff_tree_oid(&info.b_commit, &info.w_commit, "", &rev.diffopt);
 		break;
 	}
 	log_tree_diff_flush(&rev);
diff --git a/t/t3905-stash-include-untracked.sh b/t/t3905-stash-include-untracked.sh
index 2e6796725b..1c9765928d 100755
--- a/t/t3905-stash-include-untracked.sh
+++ b/t/t3905-stash-include-untracked.sh
@@ -405,4 +405,19 @@ test_expect_success 'stash show --include-untracked errors on duplicate files' '
 	test_i18ngrep "worktree and untracked commit have duplicate entries: tracked" err
 '
 
+test_expect_success 'stash show --{include,only}-untracked on stashes without untracked entries' '
+	git reset --hard &&
+	git clean -xf &&
+	>tracked &&
+	git add tracked &&
+	git stash &&
+
+	git stash show >expect &&
+	git stash show --include-untracked >actual &&
+	test_cmp expect actual &&
+
+	git stash show --only-untracked >actual &&
+	test_must_be_empty actual
+'
+
 test_done
-- 
2.31.1.751.gd2f1c929bd

Re: [PATCH 2/2] stash show: fix segfault with --{include,only}-untracked

[Junio C Hamano]

Denton Liu <liu.denton@gmail.com> writes:

> When `git stash show --include-untracked` or
> `git stash show --only-untracked` is run on a stash that doesn't include
> an untracked entry, a segfault occurs. This happens because we do not
> check whether the untracked entry is actually present and just attempt
> to blindly dereference it.
>
> Ensure that the untracked entry is present before actually attempting to
> dereference it.

Makes sense.  Thanks.

>
> Signed-off-by: Denton Liu <liu.denton@gmail.com>
> ---
>  builtin/stash.c                    |  8 ++++++--
>  t/t3905-stash-include-untracked.sh | 15 +++++++++++++++
>  2 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/stash.c b/builtin/stash.c
> index 8922a1240c..82e4829d44 100644
> --- a/builtin/stash.c
> +++ b/builtin/stash.c
> @@ -900,10 +900,14 @@ static int show_stash(int argc, const char **argv, const char *prefix)
>  		diff_tree_oid(&info.b_commit, &info.w_commit, "", &rev.diffopt);
>  		break;
>  	case UNTRACKED_ONLY:
> -		diff_root_tree_oid(&info.u_tree, "", &rev.diffopt);
> +		if (info.has_u)
> +			diff_root_tree_oid(&info.u_tree, "", &rev.diffopt);
>  		break;
>  	case UNTRACKED_INCLUDE:
> -		diff_include_untracked(&info, &rev.diffopt);
> +		if (info.has_u)
> +			diff_include_untracked(&info, &rev.diffopt);
> +		else
> +			diff_tree_oid(&info.b_commit, &info.w_commit, "", &rev.diffopt);
>  		break;
>  	}
>  	log_tree_diff_flush(&rev);
> diff --git a/t/t3905-stash-include-untracked.sh b/t/t3905-stash-include-untracked.sh
> index 2e6796725b..1c9765928d 100755
> --- a/t/t3905-stash-include-untracked.sh
> +++ b/t/t3905-stash-include-untracked.sh
> @@ -405,4 +405,19 @@ test_expect_success 'stash show --include-untracked errors on duplicate files' '
>  	test_i18ngrep "worktree and untracked commit have duplicate entries: tracked" err
>  '
>  
> +test_expect_success 'stash show --{include,only}-untracked on stashes without untracked entries' '
> +	git reset --hard &&
> +	git clean -xf &&
> +	>tracked &&
> +	git add tracked &&
> +	git stash &&
> +
> +	git stash show >expect &&
> +	git stash show --include-untracked >actual &&
> +	test_cmp expect actual &&
> +
> +	git stash show --only-untracked >actual &&
> +	test_must_be_empty actual
> +'
> +
>  test_done