Re: [PATCH] reftable/iter: fix undefined behavior in indexed_table_ref_iter_next

Hi Junio,

Thank you very much for your feedback. It is a great honor for me to receive a response from you.

I apologize for the formatting issues in my previous email. I am a new developer and still learning the community's workflow. English is not my native language, and I mistakenly added indentation when composing the email, which I now realize corrupted the patch.

I will send a corrected Version 2 (v2) of the patch shortly, ensuring that the format is preserved correctly.

Thank you for your patience and for the "lesson learned."

Best regards, Tsahi




Sent with Proton Mail secure email.

On Sunday, January 4th, 2026 at 12:22 PM, Tsahi Elkayam [off-list ref] wrote:

So I did messed up
sorry lesson learned
but still...
wow very exciting


Sent from Proton Mail for iOS.

-------- Original Message --------
On Sunday, 01/04/26 at 04:49 Junio C Hamano gitster@pobox.com wrote:

Tsahi Elkayam Tsahi.Elkayam@protonmail.com writes:

quoted

The indexed_table_ref_iter_next() function accesses ref->value.val2
without first checking the ref's value_type. This is undefined behavior
when the ref is not of type REFTABLE_REF_VAL2.

The correct pattern is already used in filtering_ref_iterator_next()
which checks value_type before accessing the appropriate union member.
Apply the same pattern here:

- Check for REFTABLE_REF_VAL2 before accessing val2 members
- Add missing check for REFTABLE_REF_VAL1 to handle single-value refs

This was marked with a "/* BUG */" comment indicating the issue was
known but not yet fixed.

Signed-off-by: Tsahi Elkayam Tsahi.Elkayam@protonmail.com
---
reftable/iter.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/reftable/iter.c b/reftable/iter.c
index 2ecc52b336..2eee65bb1e 100644
--- a/reftable/iter.c
+++ b/reftable/iter.c

What are these lines with two-whitespace indent about? When sending
a patch purely for discussion (because the actual change may be iffy
or dangerous), we sometimes deliberately corrupt the patch not to
apply mechanically, but this patch does not seem to be such a
"request for discussion" patch.