MEMCHECK: Invalid write of size

[JohnSmithBH84]

I’ve scanned PGM-index with MEMCHECK and it has triggered on PGM-index/c-interface/examples/updates.c line 20. I'm not sure whether this is an actual issue, or whether code of PGM-index is too sophisticated for MEMCHECK to understand. Do you guys have any idea?

Project version

PGM-index: master

Operating system

compiler: gcc (Debian 12.2.0-14) 12.2.0

Ubuntu 22.04.4 LTS
Linux 5.15.0-125-generic #135-Ubuntu SMP Fri Sep 27 13:53:58 UTC 2024 x86_64 x86_64 x86_64 GNU/Linux

I did this

Launched PGM-index/build/c-interface/examples/example_updates_c

I expected the following

No problem reported by MEMCHECK

I got the following

PGM-index/build/c-interface/examples/example_updates_c
==385== Memcheck, a memory error detector
==385== Copyright (C) 2002-2022, and GNU GPL'd, by Julian Seward et al.
==385== Using Valgrind-3.19.0 and LibVEX; rerun with -h for copyright info
==385== Command: PGM-index/build/c-interface/examples/example_updates_c
==385== 
==385== Warning: client switching stacks?  SP change: 0x1fff0009a0 --> 0x1ffe85f7a0
==385==          to suppress, use: --max-stackframe=8000000 or greater
==385== Invalid write of size 8
==385==    at 0x10A4A5: main (home/PGM-index/c-interface/examples/updates.c:20)