https://gitlab.synchro.net/main/sbbs/-/commit/d3706726a898cea33d7e7842
Modified Files:
src/sbbs3/filterfile.hpp findstr.c findstr.h
Log Message:
Fix Win32 debug-heap assertion freeing cached filter lists (GitLab #1099)

filterFile::listed() (and ~filterFile/reset()) freed its cached str_list
with strListFree(), which links locally into each server module (xpdev is statically linked), but built it with findstr_list(), which is dllimport'd
from sbbs.dll. So the list was allocated in sbbs.dll's CRT heap and freed
in the server module's own /MTd CRT heap. Each statically-linked CRT keeps
a per-module debug block list, so the freeing module's _free_dbg_nolock
can't find the block and asserts at debug_heap.cpp:996.

This is why the issue was debug/Windows-only and undetectable by App
Verifier: in release the UCRT heap is GetProcessHeap() (shared across
modules) so the cross-module free actually succeeds, and non-Windows
shares one libc heap -- only the Win32 debug CRT's per-module accounting notices. It was also reproducible single-threaded (deterministic heap
mismatch, not a race) and only via findstr_list() (the lone allocation
crossing the DLL boundary). Affects every filter object (ip_can,
ip_silent_can, host_can, host_exempt) in every server, since filterFile
is a header-only class compiled into each module. Present since the class
was introduced in cd30ec58a (press-5-filled).

Pair findstr_list() with a findstr_list_free() exported from the same translation unit (sbbs.dll), and call it from all three filterFile free
sites so allocation and deallocation share one heap. This also lets the strListFree() that #1099 had to comment out of reset() be restored (now
under the object mutex, since reset() runs in the shutdown path where a
late client thread may still be in listed()).

Verified: rebuilt services.dll imports both findstr_list and
findstr_list_free from sbbs.dll. Built clean on Win32/Release.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

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