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_palette_v3.py

@@ -0,0 +1,98 @@
+"""patch_palette_v3.py <pid> [--revert]
+
+v3 patch: NOP the extra refcount increment in Palette::makeModifiedPalette
+(EoR FUN_0053efe0). This stops the +1 over-increment that leaves every
+new "modified palette" at refcount=2 instead of refcount=1.
+
+Background:
+  FUN_0053efe0 = Palette::makeModifiedPalette():
+    new(0x48); Palette::Palette(this, 0x800); this->refcount++; return;
+  The "this->refcount++" makes the returned palette have refcount=2.
+  After caller's single Release, refcount=1, and the palette becomes
+  unreachable (m_pMaintainer is NULL — no cache reference) but alive.
+
+  56,664 leaked palettes in dump_9156 are all this shape: rc=1,
+  m_pMaintainer=0, m_numLinks=0.
+
+Target bytes: 0x0053effe (3 bytes inside FUN_0053efe0)
+  Original:  ff 40 24   ; inc dword [eax+0x24]   ; refcount++
+  Patched:   90 90 90   ; nop nop nop
+
+The 2013 build has the same +1 pattern at 0x0053e29e — leak likely
+exists there too, just less noticeable.
+
+Risk: some caller may assume refcount=2 and release twice; after this
+patch, the second release would crash on already-freed memory. Test on
+one client and watch closely.
+"""
+import ctypes, ctypes.wintypes as wt, sys
+
+TARGET_ADDR    = 0x0053effe
+ORIGINAL_BYTES = bytes([0xff, 0x40, 0x24])
+PATCHED_BYTES  = bytes([0x90, 0x90, 0x90])
+
+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():
+    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 * 3)(); sz = ctypes.c_size_t(0)
+    if not ReadProcessMemory(h, TARGET_ADDR, cur, 3, ctypes.byref(sz)):
+        print(f"read failed: err={ctypes.get_last_error()}"); CloseHandle(h); sys.exit(3)
+    cur_b = bytes(cur)
+    print(f"PID {pid}  bytes @ 0x{TARGET_ADDR:08x}: {' '.join(f'{b:02x}' for b in cur_b)}")
+
+    target = ORIGINAL_BYTES if revert else PATCHED_BYTES
+    expect_before = PATCHED_BYTES if revert else ORIGINAL_BYTES
+
+    if cur_b == target:
+        print(f"  already {'reverted' if revert else 'patched'}"); CloseHandle(h); return
+    if cur_b != expect_before:
+        print(f"  UNEXPECTED current bytes (wanted {' '.join(f'{b:02x}' for b in expect_before)}) — aborting")
+        CloseHandle(h); sys.exit(4)
+
+    old_prot = wt.DWORD(0)
+    if not VirtualProtectEx(h, TARGET_ADDR, 3, 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 * 3)(*target)
+    if not WriteProcessMemory(h, TARGET_ADDR, new, 3, 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, 3, old_prot.value, ctypes.byref(restored))
+
+    ReadProcessMemory(h, TARGET_ADDR, cur, 3, ctypes.byref(sz))
+    print(f"  new bytes:   {' '.join(f'{b:02x}' for b in bytes(cur))}  ({'reverted' if revert else 'patched'})")
+    CloseHandle(h)
+
+
+if __name__ == "__main__":
+    main()