fix(object): Save and load game object list in correct order by bobtista · Pull Request #2161 · TheSuperHackers/GeneralsGameCode

bobtista · 2026-01-21T00:07:38Z

Summary

Objects were saved oldest-first but loaded via prepending, which reversed their order
New saves now write objects in reverse order (newest first) so they load correctly
Old saves have their object list reversed after loading to fix the order
Bumped xfer version to 11 (Zero Hour) and 10 (Generals) for backwards compatibility

Test plan

Load an existing save from before this change, verify objects behave correctly
Create a new save, reload it, verify object order matches the original session
Verify game runs normally

Todo:

Replicate to Generals

…nal save order Co-Authored-By: Claude Opus 4.5 <[email protected]>

greptile-apps · 2026-01-21T00:10:39Z

Greptile Overview

Greptile Summary

Fixed object list order after save/load by saving objects in reverse order (newest first) so they load correctly when prepended. Old saves are automatically reversed after loading to maintain correct order. Version bumped to 10 (Generals) and 11 (Zero Hour) for backwards compatibility.

Key changes:

Save loop now traverses backwards through object list using new getPrevObject() accessor
Load operation reverses object list for old saves (version <= 9 for Generals, <= 10 for Zero Hour)
Added getPrevObject(), friend_setNextObject(), and friend_setPrevObject() accessors to Object class
Comprehensive comments explain the fix and version-specific behavior

Confidence Score: 5/5

Safe to merge with high confidence - elegant solution with proper backwards compatibility
The implementation correctly addresses the root cause by reversing save order to compensate for prepend behavior. Backwards compatibility is properly handled through version checking and list reversal for old saves. The logic is sound and well-commented.
No files require special attention

Important Files Changed

Filename	Overview
Generals/Code/GameEngine/Include/GameLogic/Object.h	Added accessor methods for previous object pointer and friend setters for list manipulation during save/load reversal
GeneralsMD/Code/GameEngine/Include/GameLogic/Object.h	Added accessor methods for previous object pointer and friend setters for list manipulation during save/load reversal
Generals/Code/GameEngine/Source/GameLogic/System/GameLogic.cpp	Saves objects in reverse order (newest first) and reverses object list after loading old saves to maintain correct order
GeneralsMD/Code/GameEngine/Source/GameLogic/System/GameLogic.cpp	Saves objects in reverse order (newest first) and reverses object list after loading old saves to maintain correct order

Sequence Diagram

sequenceDiagram
    participant Game
    participant GameLogic
    participant Xfer
    participant ObjectList
    
    alt XFER_SAVE (New Version 10/11)
        Game->>GameLogic: xfer(XFER_SAVE)
        GameLogic->>ObjectList: Find last object via getNextObject()
        loop For each object (newest to oldest)
            GameLogic->>ObjectList: Traverse backwards via getPrevObject()
            GameLogic->>Xfer: Write object data (newest first)
        end
    else XFER_LOAD (Old Save version <= 9/10)
        Game->>GameLogic: xfer(XFER_LOAD)
        loop For each saved object (oldest to newest)
            Xfer->>GameLogic: Read object data
            GameLogic->>ObjectList: Create object via prependToList()
            Note over ObjectList: Prepending reverses order
        end
        GameLogic->>ObjectList: Reverse entire list
        loop For each object
            ObjectList->>ObjectList: Swap next/prev pointers
        end
        Note over ObjectList: Correct order restored
    else XFER_LOAD (New Save version >= 10/11)
        Game->>GameLogic: xfer(XFER_LOAD)
        loop For each saved object (newest to oldest)
            Xfer->>GameLogic: Read object data
            GameLogic->>ObjectList: Create object via prependToList()
            Note over ObjectList: Order already correct
        end
    end

Stubbjax · 2026-01-21T00:11:46Z

Nice. You'd be also able to test this by saving a game with two Command Centers, then pressing H and expecting to navigate to the same Command Center before and after loading a save.

Caball009 · 2026-01-21T01:01:14Z

Nice. You'd be also able to test this by saving a game with two Command Centers, then pressing H and expecting to navigate to the same Command Center before and after loading a save.

That's not related to this change, though the underlying issue is the same.

You can uncomment this code to get the same behavior for H before and after loading a save:

GeneralsGameCode/GeneralsMD/Code/GameEngine/Source/Common/RTS/Team.cpp

Lines 2742 to 2743 in a4482e0

    
           	// since we prepended the object member pointers, reverse that list so it's just like before 
        
           //	reverse_TeamMemberList();

Mauller · 2026-01-21T08:16:36Z

Could reverse iterating during saving also fix this?

Caball009 · 2026-01-21T12:25:15Z

Could reverse iterating during saving also fix this?

I think so. That wouldn't work with already existing save games, though. Also, I think it requires changes to multiple functions.

xezon · 2026-01-22T09:33:21Z

This is a good find.

Could reverse iterating during saving also fix this?

I support this. Fixing the order of objects after creation is alright, but creating the objects in the correct order to begin with will be superior, because that will respect the right ordering even during creation, which hopefully is logically irrelevant, but technically more correct.

Caball009 · 2026-01-26T17:06:38Z

The code actually get simpler if you do the work when saving. This will only work properly for new save games.

GeneralsGameCode/GeneralsMD/Code/GameEngine/Source/GameLogic/System/GameLogic.cpp

Line 4844 in 2c26a90

for( obj = getFirstObject(); obj; obj = obj->getNextObject() )

->

Object *lastObj = nullptr;
for (obj = getFirstObject(); obj; obj = obj->getNextObject())
{
		lastObj = obj;
}

for( obj = lastObj; obj; obj = obj->getPrevObject() )

New Object member functions:

Object* getPrevObject() { return m_prev; }
const Object* getPrevObject() const { return m_prev; }

xezon · 2026-01-26T21:44:47Z

Good damn single linked list 😄

Caball009 · 2026-01-27T00:27:08Z

Does it make sense to increase the xfer version for this? It would give us a way to distinguish new save games with inverse object list if we ever needed to.

xezon · 2026-01-27T08:52:05Z

Yes can do. Is not strictly necessary but fair to do as you have described.

OmniBlade · 2026-01-27T12:54:00Z

I'd be inclined to do both, reverse the list on load if the xfer version is retail, save with correct order with new version and load as is if version is same or greater than new version.

…r old saves

xezon · 2026-01-27T18:06:09Z

Generals/Code/GameEngine/Source/GameLogic/System/GameLogic.cpp


 	// version
-	const XferVersion currentVersion = 9;
+	const XferVersion currentVersion = 10;


I assume RETAIL_COMPATIBLE_XFER_SAVE is not strictly necessary? Retail game can still load these save games correctly?

I think if an old game tries to load a new save it will just fail gracefully. I don't think this will be an issue - if someone asks a friend with TSH to create a .sav and share it with them maybe? But why would that ever happen? If we need to be able to load new saves on old game, we could use RETAIL_COMPATIBLE_XFER_SAVE

So I think the way it would work is that version 10 isn't known by retail and isn't checked so it will load the list the same way it always did which will be the new correct order for saves saved after this version, the old incorrect order for save from before this. This new version checks on load so the order loaded will be correct for builds after this PR is merged no matter what version wrote the save.

Generals/Code/GameEngine/Source/GameLogic/System/GameLogic.cpp

greptile-apps

_{2 files reviewed, 2 comments}

_{Edit Code Review Agent Settings | Greptile}

Generals/Code/GameEngine/Source/GameLogic/System/GameLogic.cpp

GeneralsMD/Code/GameEngine/Source/GameLogic/System/GameLogic.cpp

xezon

Looks correct. See suggestion from Caball regarding comment tag.

There are a bunch of TODO's in the opening description.

bobtista · 2026-02-24T15:35:45Z

Looks correct. See suggestion from Caball regarding comment tag.

There are a bunch of TODO's in the opening description.

Tested locally, looks good

bugfix(savegame): Restore object list order after load to match origi…

e4dc439

…nal save order Co-Authored-By: Claude Opus 4.5 <[email protected]>

bobtista added 2 commits January 27, 2026 08:21

bugfix(savegame): Save objects in reverse order and fix load order fo…

d342157

…r old saves

replicate to Generals

61a136a

bobtista changed the title ~~bugfix(savegame): Restore object list order after load to match original save order~~ bugfix(savegame): Fix object list order after load Jan 27, 2026

xezon reviewed Jan 27, 2026

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Caball009 reviewed Jan 27, 2026

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greptile-apps bot reviewed Jan 28, 2026

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xezon approved these changes Jan 28, 2026

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fix(savegame): Use consistent @fix tag in save section comments

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xezon approved these changes Feb 25, 2026

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xezon changed the title ~~bugfix(savegame): Fix object list order after load~~ fix(logic): Save and load game object list in correct order Feb 25, 2026

xezon added Minor Severity: Minor < Major < Critical < Blocker and removed Major Severity: Minor < Major < Critical < Blocker labels Feb 25, 2026

xezon changed the title ~~fix(logic): Save and load game object list in correct order~~ fix(object): Save and load game object list in correct order Feb 25, 2026

xezon added the Saveload Is Saveload/Xfer related label Feb 25, 2026

xezon merged commit daf86de into TheSuperHackers:main Feb 25, 2026
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Summary

Test plan

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Greptile Overview

Greptile Summary

Confidence Score: 5/5

Important Files Changed

Sequence Diagram

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