Save games cannot be loaded on non-Windows builds

[bobtista]

Prerequisites

• I have searched for similar issues and confirmed this is not a duplicate

Game Version

• Command & Conquer Generals
• Command & Conquer Generals: Zero Hour

Bug Description

On non-Windows builds a save game cannot be loaded. The load reads the save, throws while reading the CHUNK_GameStateMap block, and GameState::loadGame returns SC_INVALID_DATA, so the game returns to the shell instead of entering the save.

GameState::portableMapPathToRealMapPath builds the real path, validates it, and then lowercases the result before returning it:

portable   save\defcon6.map
returned   /home/user/.local/share/command and conquer generals zero hour data/save/defcon6.map

GameStateMap::xfer then passes that lowercased path to GameState::isInSaveDirectory, which compares it against the real Save directory:

save dir   /home/user/.local/share/Command and Conquer Generals Zero Hour Data/Save/

The first validation inside portableMapPathToRealMapPath succeeds, because it runs before the lowercasing. The later check in GameStateMap::xfer fails, because Save is not save on a case sensitive file system, and the block throws.

This is a regression from #1058. Before that change isInSaveDirectory compared case insensitively:

Bool GameState::isInSaveDirectory(const AsciiString& path) const
{
	return path.startsWithNoCase(getSaveDirectory());
}

#1058 replaced that with FileSystem::isPathInDirectory, which compares case insensitively only on Windows. The lowercasing in portableMapPathToRealMapPath and the check in GameStateMap::xfer are both original code and unchanged since the initial commit.

The failure is silent in a release build, because loadGame catches the exception with catch( ... ) and the DEBUG_CRASH that names the failing block is compiled out.

Reproduction Steps

1. On a non-Windows build, start a mission or skirmish and save the game.
2. Load that save from the in-game load menu.
3. Observe the game does not enter the save and returns to the shell.
4. Repeat on a Windows build. The save loads.

Additional Context

• The default user data directory name is mixed case (GlobalData.cpp, leaf name Command and Conquer Generals Zero Hour Data), so this affects a default installation rather than only unusual paths.
• isInSaveDirectory is also used by the restart path and by map name checks in GameLogic, which receive the same lowercased name.
• FileSystem::isPathInDirectory itself should stay case sensitive off Windows. [GEN][ZH] Fix security issue in map transfer by validating file paths when creating real paths from portable paths #1058 added it to validate network supplied portable paths before a transferred file is written, so relaxing it globally would weaken that check.