fix(logic): Add nullptr check to thisPlayer in GameLogic::logicMessageDispatcher

[Caball009]

This PR changes the nullptr assertion on thisPlayer in GameLogic::logicMessageDispatcher to an early return. Although there are a couple of places in this function that check explicitly for it, a lot of code assumes that this pointer is not null, so it makes sense to check that up front.

Commit 1 adds the check.
Commit 2 removes code that's become redundant (implicitly).
Commit 3 changes msg->getPlayerIndex to thisPlayer->getPlayerIndex for the sole purpose of consistency with code that already uses the latter.

TODO:

• Replicate in Generals.

[Mauller]

on 645 we have

case GameMessage::MSG_ENABLE_RETALIATION_MODE:
{
	//Logically turns on or off retaliation mode for a specified player.
	Int playerIndex = msg->getArgument( 0 )->integer;
	Bool enableRetaliation = msg->getArgument( 1 )->boolean;

	Player *player = ThePlayerList->getNthPlayer( playerIndex );
	if( player )
	{
		player->setLogicalRetaliationModeEnabled( enableRetaliation );
	}
	break;
}

I wonder if this needs clarifying that player here is a targetPlayer and not the same as thisPlayer

I am guessing that Int playerIndex = msg->getArgument( 0 )->integer; returns a different value compared to msg->getPlayerID

[stephanmeesters]

I wonder if this needs clarifying that player here is a targetPlayer and not the same as thisPlayer

I am guessing that Int playerIndex = msg->getArgument( 0 )->integer; returns a different value compared to msg->getPlayerID

I have a PR planned for this one which makes the change that player = thisPlayer, which seemed to pass 1k replays, but wanted to test that a bit more

[greptile-apps]

Greptile Summary

This PR hardens GameLogic::logicMessageDispatcher by replacing the debug-only DEBUG_ASSERTCRASH on thisPlayer with an upfront nullptr guard that issues a DEBUG_CRASH and early-returns, making the function safe in both debug and release builds. Follow-up commits remove the now-redundant per-case null checks and standardise msg->getPlayerIndex() calls to thisPlayer->getPlayerIndex() for consistency.

Key changes:

• Upfront guard (GameLogicDispatch.cpp:353–357): thisPlayer == nullptr now causes an early return instead of an assertion-crash, closing the gap for release builds where the assertion was a no-op.
• Redundant check removal: Eliminates local player variables and per-case null checks in MSG_CREATE_SELECTED_GROUP, MSG_REMOVE_FROM_SELECTED_GROUP, MSG_DESTROY_SELECTED_GROUP, MSG_CREATE_TEAM*, MSG_SELECT_TEAM*, MSG_ADD_TEAM*, and the MSG_PURCHASE_SCIENCE sanity condition.
• Consistency cleanup: Replaces msg->getPlayerIndex() with thisPlayer->getPlayerIndex() in MSG_SELF_DESTRUCT loop comparison and MSG_LOGIC_CRC cache indexing.
• As noted in the PR TODO, the equivalent change still needs to be replicated in the Generals/ directory.

Confidence Score: 5/5

• This PR is safe to merge — the changes are logically sound, well-scoped, and reduce crash risk in release builds.
• The upfront guard is the correct approach and was clearly needed given how much of the function assumed thisPlayer was non-null. All removed null checks are provably redundant after the early return. The msg->getPlayerIndex() vs thisPlayer->getPlayerIndex() substitutions are semantically equivalent since thisPlayer is looked up via msg->getPlayerIndex() in the first place. No custom rules are violated by the introduced code.
• No files require special attention.

Important Files Changed

Filename	Overview
GeneralsMD/Code/GameEngine/Source/GameLogic/System/GameLogicDispatch.cpp	Adds an upfront nullptr guard for thisPlayer with an early return, then removes now-redundant per-case null checks across MSG_CREATE_SELECTED_GROUP, MSG_REMOVE_FROM_SELECTED_GROUP, MSG_DESTROY_SELECTED_GROUP, MSG_CREATE_TEAM*, MSG_SELECT_TEAM*, MSG_ADD_TEAM*, and MSG_PURCHASE_SCIENCE. Also replaces scattered msg->getPlayerIndex() calls with thisPlayer->getPlayerIndex() for consistency.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[logicMessageDispatcher called] --> B[Resolve thisPlayer via\nThePlayerList->getNthPlayer]
    B --> C{thisPlayer == nullptr?}
    C -- Yes --> D[DEBUG_CRASH + early return]
    C -- No --> E[Setup currentlySelectedGroup\nif in-game network msg]
    E --> F[Switch on msgType]
    F --> G[MSG_CREATE_SELECTED_GROUP\nuses thisPlayer->getPlayerMask]
    F --> H[MSG_REMOVE_FROM_SELECTED_GROUP\nuses thisPlayer->getPlayerMask]
    F --> I[MSG_DESTROY_SELECTED_GROUP\nsetCurrentlySelectedAIGroup]
    F --> J[MSG_CREATE/SELECT/ADD_TEAM*\nuses thisPlayer directly]
    F --> K[MSG_LOGIC_CRC\ncached via thisPlayer->getPlayerIndex]
    F --> L[MSG_PURCHASE_SCIENCE\nsanity: SCIENCE_INVALID only]
    F --> M[... other cases ...]

Loading

_{Last reviewed commit: 7c8b814}

[xezon]

Nice cleanup. But there is CRC mismatch risk.

Also there are 2 more msg->getPlayerIndex() in commented and compiled out code.

[xezon]

Instead of doing thisPlayer->getPlayerIndex() you could also add a const int playerIndex = msg->getPlayerIndex() at the begin of the function and then use that.

[xezon]

Very hot. Needs replication in Generals.