Initial commit — leak-hunt project complete

Five bugs identified and patched in retail Asheron's Call client:
- v3b: palette refcount over-increment (3-byte NOP at two sites)
- v5: RenderSurface PurgeResource no-op stub (vtable slot 2 thunk)
- v11: two dangling-pointer crash guards (NULL-check + reorder)
- v14: CEnvCell::Destroy ClipPlaneList leak (18-byte JMP to cleanup thunk)
- v22: unpacker stale-pointer SEH guard (whole-function __try/__except)

All five ship in leakfix.dll (117 KB, SHA d282f23c…) which is loaded
by acclient.exe at process start via PE import table patching by
tools/install_leakfix.py.

Controlled 15-client fleet soak: unpatched control died at 26h with
palette exhaustion; all 14 patched clients survived past that point
and reached ≥5-day uptime.

Residual ~15 MB/h growth traced to d3d9.dll's internal slab allocator
(260KB surface backing buffers retained after Release). See REPORT.md
§10 for the full investigation; conclusion is that it's unfixable from
outside d3d9.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

tools/patch_freeobject_v2.py

@@ -0,0 +1,96 @@
+"""patch_freeobject_v2.py <pid> [--revert]
+
+v2 patch: force DBOCache::FreeObject to always take the DELETE path
+(never add to freelist). This causes every Release-to-refcount-1 to
+invoke the proper destructor, which calls operator delete[] on the
+Palette ARGB buffer (and similar for other DBObj-derived classes).
+
+Target byte: EoR 0x004169bf
+Original:    0x74  (jz delete_path)
+Patched:     0xeb  (jmp delete_path)  — unconditional
+
+Effect:
+  - DBOCache::FreeObject(this, obj) now always:
+    obj->ReleaseSubObjects(); obj->in_use = 0; this->vt[0x44](obj);
+  - Skips the "if freelist enabled, push to freelist" branch
+  - Affects ALL DBObj-derived classes (not just Palette)
+
+Risk:
+  - Performance: cache misses now require full alloc + load instead of
+    reuse from freelist. For frequently-used classes, may add latency.
+  - Correctness: should be safe — delete path uses proper destructor
+    that already handles all field cleanup.
+"""
+import ctypes, ctypes.wintypes as wt, sys
+
+TARGET_ADDR  = 0x004169bf
+EXPECTED_VAL = 0x74    # jz
+PATCHED_VAL  = 0xeb    # jmp
+
+PROCESS_VM_READ           = 0x0010
+PROCESS_VM_WRITE          = 0x0020
+PROCESS_VM_OPERATION      = 0x0008
+PROCESS_QUERY_INFORMATION = 0x0400
+PAGE_EXECUTE_READWRITE    = 0x40
+
+k32 = ctypes.windll.kernel32
+OpenProcess        = k32.OpenProcess
+OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]; OpenProcess.restype = wt.HANDLE
+CloseHandle        = k32.CloseHandle
+CloseHandle.argtypes = [wt.HANDLE]; CloseHandle.restype = wt.BOOL
+ReadProcessMemory  = k32.ReadProcessMemory
+ReadProcessMemory.argtypes = [wt.HANDLE, wt.LPCVOID, wt.LPVOID, ctypes.c_size_t,
+                              ctypes.POINTER(ctypes.c_size_t)]
+ReadProcessMemory.restype = wt.BOOL
+WriteProcessMemory = k32.WriteProcessMemory
+WriteProcessMemory.argtypes = [wt.HANDLE, wt.LPVOID, wt.LPCVOID, ctypes.c_size_t,
+                               ctypes.POINTER(ctypes.c_size_t)]
+WriteProcessMemory.restype = wt.BOOL
+VirtualProtectEx   = k32.VirtualProtectEx
+VirtualProtectEx.argtypes = [wt.HANDLE, wt.LPVOID, ctypes.c_size_t,
+                             wt.DWORD, ctypes.POINTER(wt.DWORD)]
+VirtualProtectEx.restype = wt.BOOL
+
+
+def main():
+    if len(sys.argv) < 2:
+        print("usage: patch_freeobject_v2.py <pid> [--revert]"); sys.exit(1)
+    pid    = int(sys.argv[1])
+    revert = "--revert" in sys.argv
+
+    h = OpenProcess(PROCESS_VM_READ|PROCESS_VM_WRITE|PROCESS_VM_OPERATION|PROCESS_QUERY_INFORMATION,
+                    False, pid)
+    if not h:
+        print(f"OpenProcess({pid}) failed: err={ctypes.get_last_error()}"); sys.exit(2)
+
+    cur = ctypes.c_ubyte(0); sz = ctypes.c_size_t(0)
+    if not ReadProcessMemory(h, TARGET_ADDR, ctypes.byref(cur), 1, ctypes.byref(sz)):
+        print(f"read failed: err={ctypes.get_last_error()}"); CloseHandle(h); sys.exit(3)
+    print(f"PID {pid}  byte @ 0x{TARGET_ADDR:08x} current: 0x{cur.value:02x}")
+
+    target = EXPECTED_VAL if revert else PATCHED_VAL
+    expect_before = PATCHED_VAL if revert else EXPECTED_VAL
+
+    if cur.value == target:
+        print(f"  already {'reverted' if revert else 'patched'}")
+        CloseHandle(h); return
+    if cur.value != expect_before:
+        print(f"  UNEXPECTED current value (wanted 0x{expect_before:02x}) — aborting")
+        CloseHandle(h); sys.exit(4)
+
+    old_prot = wt.DWORD(0)
+    if not VirtualProtectEx(h, TARGET_ADDR, 1, PAGE_EXECUTE_READWRITE, ctypes.byref(old_prot)):
+        print(f"VirtualProtectEx failed: err={ctypes.get_last_error()}"); CloseHandle(h); sys.exit(5)
+    new = ctypes.c_ubyte(target)
+    if not WriteProcessMemory(h, TARGET_ADDR, ctypes.byref(new), 1, ctypes.byref(sz)):
+        print(f"write failed: err={ctypes.get_last_error()}"); CloseHandle(h); sys.exit(6)
+    restored = wt.DWORD(0)
+    VirtualProtectEx(h, TARGET_ADDR, 1, old_prot.value, ctypes.byref(restored))
+
+    ReadProcessMemory(h, TARGET_ADDR, ctypes.byref(cur), 1, ctypes.byref(sz))
+    print(f"  new value:   0x{cur.value:02x}  ({'reverted' if revert else 'patched'})")
+    CloseHandle(h)
+
+
+if __name__ == "__main__":
+    main()