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_heap_solo_scan.py

@@ -0,0 +1,154 @@
+"""position_heap_solo_scan.py <pid>
+
+Variant of position_host_scan that filters to ONLY Positions which
+look like standalone heap allocations (vs embedded into a bigger
+struct).
+
+Heuristic for "standalone heap allocation":
+  - Bytes right before the Position vtable have a typical heap-block
+    header pattern (small DWORD = allocation size, then a possibly-NULL
+    block-id, then padding/flags).
+  - OR there is a ref-counted wrapper vtable at offset -8 (the
+    PositionPropertyValue pattern).
+  - The +96..+128 region after the Position is either NULL/heap-free
+    (suggesting nothing follows the Position in the same block).
+
+Goal: classify Positions into:
+  (A) embedded in a larger object — host vtable found at offset -4
+      through -16 (the Position is just a field of e.g. a PhysicsObj
+      or NetBlob).
+  (B) inside a ref-counted property wrapper — vtable at -8
+      (PositionPropertyValue layout).
+  (C) heap-solo at offset 0 — allocated as `new Position(...)`
+      directly, no enclosing object.
+  (D) part of an array — another Position vtable 96 bytes away.
+
+The leaking class is whichever bucket dominates the delta between
+heavy-looter and idle character.
+"""
+import ctypes
+import ctypes.wintypes as wt
+import struct
+import sys
+from collections import Counter, defaultdict
+
+POSITION_VT = 0x00797910
+ACCLIENT_MIN = 0x00400000
+ACCLIENT_MAX = 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 classify(data, off):
+    """Return (bucket, evidence_value). bucket in {'array','ppv',
+    'embedded','solo','unknown'}."""
+    # array: Position vtable 96 bytes earlier or later
+    if off >= 96:
+        prev = struct.unpack_from("<I", data, off - 96)[0]
+        if prev == POSITION_VT:
+            return ('array_prev', prev)
+    if off + 96 + 4 <= len(data):
+        nxt = struct.unpack_from("<I", data, off + 96)[0]
+        if nxt == POSITION_VT:
+            return ('array_next', nxt)
+    # ppv: vtable at off-8, refcount-shaped dword at off-4
+    if off >= 8:
+        m8 = struct.unpack_from("<I", data, off - 8)[0]
+        m4 = struct.unpack_from("<I", data, off - 4)[0]
+        if ACCLIENT_MIN <= m8 <= ACCLIENT_MAX and 0 < m4 < 0x100000:
+            return ('ppv', m8)
+    # embedded: any acclient code-range vtable at offsets -32..-4
+    if off >= 32:
+        for d in range(-32, 0, 4):
+            v = struct.unpack_from("<I", data, off + d)[0]
+            if ACCLIENT_MIN <= v <= ACCLIENT_MAX:
+                return ('embedded', v)
+    # solo: nothing identifying
+    return ('solo', 0)
+
+
+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
+
+    bucket_counts = Counter()
+    embedded_vt_counts = Counter()
+    ppv_vt_counts = Counter()
+    array_off_counts = Counter()
+
+    total = 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
+                for off in range(0, end, 4):
+                    if struct.unpack_from("<I", data, off)[0] == POSITION_VT:
+                        total += 1
+                        b, ev = classify(data, off)
+                        bucket_counts[b] += 1
+                        if b == 'embedded':
+                            embedded_vt_counts[ev] += 1
+                        elif b == 'ppv':
+                            ppv_vt_counts[ev] += 1
+                        elif b.startswith('array'):
+                            array_off_counts[b] += 1
+        addr = (mbi.BaseAddress or 0) + mbi.RegionSize
+        if addr >= 0x80000000:
+            break
+
+    print(f"PID {pid}: {total} Position instances scanned")
+    print()
+    print("Bucket distribution:")
+    for b, n in bucket_counts.most_common():
+        pct = 100.0 * n / max(1, total)
+        print(f"  {b:>12}: {n:>7}  ({pct:5.1f}%)")
+    print()
+    print("Top 'embedded' host vtables (Position is a member of class):")
+    for v, n in embedded_vt_counts.most_common(15):
+        print(f"  0x{v:08x}  count={n:>6}")
+    print()
+    print("Top 'ppv' wrapper vtables (Position inside ref-counted holder):")
+    for v, n in ppv_vt_counts.most_common(10):
+        print(f"  0x{v:08x}  count={n:>6}")
+    print()
+    print("Array adjacency:")
+    for b, n in array_off_counts.most_common():
+        print(f"  {b}: {n}")
+
+    k.CloseHandle(h)
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(scan(int(sys.argv[1])))