[disable_cameras] Sometimes crash not prevented

[jensewe]

Happens when joining Survivors from Spectators at start of Versus second half, with First Map - Skip Intro Cutscenes installed.

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https://github.com/shqke/sp_public/blob/aadfd7c425e5a585a197160474551642b11d3115/disable_cameras/scripting/disable_cameras.sp#L21 It looks like changing to IsClientConnected would help, just weird and not guaranteed. I really doubt it's caused by a little gap between Connected and InGame for bots, still I'm not aware of how and when Connected and PutInServer are called for bots.

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Crash dumps QHQB-NAAW-M456 35K3-GYJ3-Z7H5

[shqke]

https://github.com/ValveSoftware/Source-1-Games/issues/3388#issuecomment-830781131

I can only advise to change method of disabling intros, or to attempt to understand what's been missing in said plugin.

[jensewe]

Came up with a thought that even though the camera is disabled, the Think function could still be running. So I tried a bit with SDKHook hooking, blocking Think and it seems I'm right as SDKHook Think was actually called and no crash. Still I'm not confident to confirm a fix because I've been doing CTriggerCamera cases only, while under no impression of what maps contain the other two. Would be appreciated if there's info.

Modified code below:

Action SDK_CTriggerCamera_OnThink(int entity)
{
    SDKUnhook(entity, SDKHook_Think, SDK_CTriggerCamera_OnThink);

    if (GetEntProp(entity, Prop_Data, "m_state") == 0) {
        PrintToChatAll("\x04CTriggerCamera Think");
        return Plugin_Handled;
    }

    return Plugin_Continue;
}

Action SDK_CMoveableCamera_OnThink(int entity)
{
    SDKUnhook(entity, SDKHook_Think, SDK_CMoveableCamera_OnThink);

    static int iOffs_m_bActive = -1;
    if (iOffs_m_bActive == -1) {
        iOffs_m_bActive = FindDataMapInfo(entity, "m_iszScriptId") + 72;
    }

    if (GetEntData(entity, iOffs_m_bActive, 1) == 0) {
        PrintToChatAll("\x04CMoveableCamera Think");
        return Plugin_Handled;
    }

    return Plugin_Continue;
}

public void OnClientDisconnect(int client)
{
    if (!IsClientInGame(client)) {
        return;
    }

    int viewEntity = GetEntPropEnt(client, Prop_Send, "m_hViewEntity");
    if (!IsValidEdict(viewEntity)) {
        return;
    }

    char cls[64];
    GetEdictClassname(viewEntity, cls, sizeof(cls));
    if (strncmp(cls, "point_viewcontrol", 17) == 0) {
        // Matches CSurvivorCamera, CTriggerCamera
        if (strcmp(cls[17], "_survivor") == 0 || cls[17] == '\0') {
            // Disable entity to prevent CMoveableCamera::FollowTarget to cause a crash
            // m_hTargetEnt EHANDLE is not checked for existence and can be NULL
            // CBaseEntity::GetAbsAngles being called on causing a crash
            AcceptEntityInput(viewEntity, "Disable");

            if (cls[17] == '\0') {
                SDKHook(viewEntity, SDKHook_Think, SDK_CTriggerCamera_OnThink);
            } else {
                SDKHook(viewEntity, SDKHook_Think, SDK_CMoveableCamera_OnThink);
            }
        }

        // Matches CTriggerCameraMultiplayer
        if (strcmp(cls[17], "_multiplayer") == 0) {
            AcceptEntityInput(viewEntity, "RemovePlayer", client);
            SDKHook(viewEntity, SDKHook_Think, SDK_CMoveableCamera_OnThink);
        }
    }
}

[shqke]

Why are you trying to enforce a fix to be placed into my plugin for a problem that's caused by a different plugin? 🤔

There's no convenient entry point to patch FollowCamera NULL dereference, and the only problematic case (known to me) that could happen on a clean sourcemod/game installation is taken care of by my plugin.

[jensewe]

Thanks. looks like the skip intro actually raises this one:

// STOP SCENE
SetVariantString("!self");
AcceptEntityInput(entity, "StartMovement");

StartMovement runs regardless of the active state handled by Enable/Disable, guess I can prove it later and contact the author for a fix to it. Thank you for your patience and helps!