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/position_array_inspect.py

@@ -0,0 +1,125 @@
+"""position_array_inspect.py <pid> -- for arrays of Positions (96.6%
+of all hits), find the bytes immediately BEFORE the array start and
+immediately AFTER the array end. This is where the array allocator's
+header would live, or where the containing DArray/SmartArray descriptor
+points.
+"""
+import ctypes, ctypes.wintypes as wt, struct, sys
+from collections import Counter
+
+POSITION_VT = 0x00797910
+SIZEOF_POSITION = 72
+ACMIN, ACMAX = 0x00400000, 0x00900000
+
+PROCESS_VM_READ = 0x10
+PROCESS_QUERY_INFORMATION = 0x400
+
+class MBI(ctypes.Structure):
+    _fields_ = [('BaseAddress', ctypes.c_void_p),
+                ('AllocationBase', ctypes.c_void_p),
+                ('AllocationProtect', wt.DWORD),
+                ('PartitionId', wt.WORD),
+                ('RegionSize', ctypes.c_size_t),
+                ('State', wt.DWORD),
+                ('Protect', wt.DWORD),
+                ('Type', wt.DWORD)]
+
+k = ctypes.windll.kernel32
+k.OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]; k.OpenProcess.restype = wt.HANDLE
+k.CloseHandle.argtypes = [wt.HANDLE]; k.CloseHandle.restype = wt.BOOL
+k.ReadProcessMemory.argtypes = [wt.HANDLE, wt.LPCVOID, wt.LPVOID, ctypes.c_size_t,
+                                ctypes.POINTER(ctypes.c_size_t)]
+k.ReadProcessMemory.restype = wt.BOOL
+k.VirtualQueryEx.argtypes = [wt.HANDLE, ctypes.c_void_p, ctypes.POINTER(MBI), ctypes.c_size_t]
+k.VirtualQueryEx.restype = ctypes.c_size_t
+
+
+def scan(pid):
+    h = k.OpenProcess(PROCESS_VM_READ | PROCESS_QUERY_INFORMATION, False, pid)
+    if not h:
+        print(f"OpenProcess err={ctypes.get_last_error()}"); return 1
+
+    # For each "array head" (Position with no Position 72 bytes before),
+    # collect: (array_len, bytes 16 BEFORE first position).
+    # For each "array tail" (Position with no Position 72 bytes after),
+    # collect: bytes 16 AFTER end of position.
+    array_lens = Counter()
+    head_minus_4 = Counter()
+    head_minus_8 = Counter()
+    head_minus_12 = Counter()
+    head_minus_16 = Counter()
+    array_size_bytes = Counter()
+    total_arrays = 0
+
+    mbi = MBI(); addr = 0
+    while k.VirtualQueryEx(h, addr, ctypes.byref(mbi), ctypes.sizeof(mbi)):
+        pr = mbi.Protect & 0xff
+        if (mbi.State == 0x1000 and mbi.Type == 0x20000
+                and pr in (0x04, 0x40)):
+            buf = (ctypes.c_ubyte * mbi.RegionSize)()
+            sz = ctypes.c_size_t(0)
+            if k.ReadProcessMemory(h, mbi.BaseAddress, buf, mbi.RegionSize, ctypes.byref(sz)):
+                data = bytes(buf[:sz.value])
+                end = (len(data) // 4) * 4
+                pos_offs = []
+                for off in range(0, end, 4):
+                    if struct.unpack_from("<I", data, off)[0] == POSITION_VT:
+                        pos_offs.append(off)
+                pos_set = set(pos_offs)
+                # find array heads
+                for off in pos_offs:
+                    if (off - SIZEOF_POSITION) in pos_set:
+                        continue  # not a head
+                    # Walk forward to find the tail
+                    tail = off
+                    length = 1
+                    while (tail + SIZEOF_POSITION) in pos_set:
+                        tail += SIZEOF_POSITION
+                        length += 1
+                    if length < 2:
+                        continue  # not really an array
+                    total_arrays += 1
+                    array_lens[length] += 1
+                    array_size_bytes[length * SIZEOF_POSITION] += 1
+                    # Bytes BEFORE head
+                    if off >= 16:
+                        m4 = struct.unpack_from("<I", data, off - 4)[0]
+                        m8 = struct.unpack_from("<I", data, off - 8)[0]
+                        m12 = struct.unpack_from("<I", data, off - 12)[0]
+                        m16 = struct.unpack_from("<I", data, off - 16)[0]
+                        head_minus_4[m4] += 1
+                        head_minus_8[m8] += 1
+                        head_minus_12[m12] += 1
+                        head_minus_16[m16] += 1
+        addr = (mbi.BaseAddress or 0) + mbi.RegionSize
+        if addr >= 0x80000000:
+            break
+
+    print(f"PID {pid}: {total_arrays} Position arrays found")
+    print()
+    print("Top array lengths (positions per array):")
+    for length, n in array_lens.most_common(15):
+        print(f"  len={length:>5}  count={n:>6}  bytes/array={length*SIZEOF_POSITION:>7}")
+    print()
+    print("Top values at offset -4 of array head (likely refcount/size/flags):")
+    for v, n in head_minus_4.most_common(8):
+        print(f"  {v:#010x}  count={n}")
+    print()
+    print("Top values at offset -8 of array head:")
+    for v, n in head_minus_8.most_common(8):
+        print(f"  {v:#010x}  count={n}")
+    print()
+    print("Top values at offset -12 of array head:")
+    for v, n in head_minus_12.most_common(8):
+        print(f"  {v:#010x}  count={n}")
+    print()
+    print("Top values at offset -16 of array head:")
+    for v, n in head_minus_16.most_common(8):
+        print(f"  {v:#010x}  count={n}")
+
+    k.CloseHandle(h)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(scan(int(sys.argv[1])))