Subject: Re: [PATCH v2] symlinks: use unsigned int for flags

From: Junio C Hamano <[email-masked]>
Date: Wed, 21 Jan 2026 10:04:32 -0800

Tian Yuchen <[email-masked]> writes:

> The 'flags' and 'track_flags' fields in symlinks.c are used
> strictly as a collection of bits (using bitwise operators including
> &, |, ~). Using a signed integer for bitmasks may lead to undefined
> behavior with shift operations and logic errors if the MSB is touched.

Which we do not do, so the "signed can lead to bugs" is a valid
concern and moving to unsigned is a good mitigation, but ...

>
> Change these fields from 'int' to 'unsigned int' to align with C
> standards and typical usage patterns.

... I'd tone it down a bit by replacing "aling with C standards and
typical" with "match our", if I were writing this.

>
> Signed-off-by: Tian Yuchen <[email-masked]>
>
> ---
> Changes in v2:
>
> Decouple definition of 'ret' and 'saved_errno' from 'save_flags'.
> 'ret' captures the return value of lstat() which can be -1, so it
> must remain signed. Same applies to 'saved_errno'.
>
> (Thanks to Patrick Steinhardt for spotting this)

Yes, indeed.  Thanks.