Fix startup crash: use ClientCmd for fullbright; sanitize owner netvars

- Poking VEngineCvar004/ConVar vtables directly crashed before the main menu
  (ConVar uses a secondary IConVar vtable). Use the stable IVEngineClient
  ClientCmd slot 7 for mat_fullbright instead.
- Reject out-of-range m_hOwnerEntity/m_hOwner offsets: the resolver found a
  bogus negative owner offset (-136296061), which could make item-ESP weapon
  ownership read wild memory.

2 files changed, 15 insertions, 27 deletions

diff --git a/src/hl2h.cpp b/src/hl2h.cpp
index ebb9b14..375cd5a 100644
--- a/src/hl2h.cpp
+++ b/src/hl2h.cpp
@@ -131,32 +131,16 @@ static int g_modified_logged = 0;
 // GetName, GetHelpText, IsRegistered, GetDLLIdentifier; ConVar then adds
 // SetValue(const char*), SetValue(float), SetValue(int) -> slot 11.
 bool cvar_set_int(const char *name, int value) {
-  if (!name)
+  if (!name || !g_iface.engine)
     return false;
-  if (g_iface.cvar) {
-    using FindVarFn = void *(*)(void *, const char *);
-    void *var = vfunc<FindVarFn>(g_iface.cvar, 12)(g_iface.cvar, name);
-    if (var) {
-      using GetNameFn = const char *(*)(void *);
-      const char *got = vfunc<GetNameFn>(var, 5)(var);
-      if (got && strcmp(got, name) == 0) {
-        using SetIntFn = void (*)(void *, int);
-        vfunc<SetIntFn>(var, 11)(var, value);
-        return true;
-      }
-    }
-  }
-  // Fallback for an engine that does not expose VEngineCvar004: ClientCmd
-  // slot 7. Cheat-protected cvars may still be rejected.
-  if (g_iface.engine) {
-    char cmd[96];
-    snprintf(cmd, sizeof(cmd), "%s %d", name, value);
-    using CmdFn = void (*)(void *, const char *);
-    vfunc<CmdFn>(g_iface.engine, 7)(g_iface.engine, cmd);
-    logd("cvar: fallback command '%s'", cmd);
-    return true;
-  }
-  return false;
+  // Use the stable IVEngineClient ClientCmd slot rather than poking ConVar's
+  // vtable; the installed VEngineCvar004 layout differs enough to crash.
+  char cmd[96];
+  snprintf(cmd, sizeof(cmd), "%s %d", name, value);
+  using CmdFn = void (*)(void *, const char *);
+  vfunc<CmdFn>(g_iface.engine, 7)(g_iface.engine, cmd);
+  logd("cvar: command '%s'", cmd);
+  return true;
 }
 
 void note_modified(const CUserCmd *cmd, int flags, const float *vel) {
diff --git a/src/netvars.cpp b/src/netvars.cpp
index adb5a6a..834aa2f 100644
--- a/src/netvars.cpp
+++ b/src/netvars.cpp
@@ -93,9 +93,13 @@ static void collect_netvars(uintptr_t table, uintptr_t base_off, int depth) {
                g_net.activeweapon < 0) {
       g_net.activeweapon = (int)(base_off + (uint32_t)poff);
     } else if (strcmp(pname2, "m_hOwnerEntity") == 0 && g_net.owner < 0) {
-      g_net.owner = (int)(base_off + (uint32_t)poff);
+      int off = (int)(base_off + (uint32_t)poff);
+      if (off > 0 && off < 0x2000)
+        g_net.owner = off;
     } else if (strcmp(pname2, "m_hOwner") == 0 && g_net.weapon_owner < 0) {
-      g_net.weapon_owner = (int)(base_off + (uint32_t)poff);
+      int off = (int)(base_off + (uint32_t)poff);
+      if (off > 0 && off < 0x2000)
+        g_net.weapon_owner = off;
     } else if (strcmp(pname2, "m_iTeamNum") == 0 && g_net.teamnum < 0) {
       g_net.teamnum = (int)(base_off + (uint32_t)poff);
     } else if (strcmp(pname2, "m_vecOrigin") == 0 && g_net.origin < 0) {