Incorrect case for default TextureGroup name causes duplicate Default/default groups

[Caritusy]

Description

When decompiling a GameMaker project, the generated Texture Group name for the default texture group appears to be default, while GameMaker's built-in/default Texture Group is named Default.

This creates a case-only duplicate Texture Group:

Texture Group - Default
Texture Group - default

On Windows, since the filesystem is case-insensitive, both Default and default may point to the same cache output file, such as:

TextureGroups\_2048_131\default.xml

This can cause GameMaker's AssetCompiler to fail when compiling texture pages, especially during parallel builds.

Error Log

Example error from GameMaker:

Texture Group - Default
Texture Group - stage1
Texture Group - __YY__0fallbacktexture.png_YYG_AUTO_GEN_TEX_GROUP_NAME_
Texture Group - effects
Texture Group - default
Texture Group - stage2
Texture Group - stage4
Texture Group - stage3
Texture Group - system

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.AggregateException: One or more errors occurred. 
(The process cannot access the file 
'C:\Users\Requiem\AppData\Roaming\GameMakerStudio2-LTS2026\Cache\GMS2CACHE\K3P_0103_N_796250F5\Default\TextureGroups\_2048_131\default.xml' 
because it is being used by another process.)

 ---> System.IO.IOException: The process cannot access the file 
'...\TextureGroups\_2048_131\default.xml' 
because it is being used by another process.

   at GMAssetCompiler.TextureGroup.SaveCacheFile(String _cacheFile)
   at GMAssetCompiler.TexturePage.Compile()

The build command was using parallel jobs:

Igor.exe -j=8 ... Windows Run

Cause

The decompiler seems to output the default Texture Group as:

default

However, GameMaker itself expects/creates the default Texture Group as:

Default

Because both names only differ by case, this creates a problematic duplicate on Windows.

Expected Behavior

The decompiled project should use the same default Texture Group name as GameMaker:

Default

There should not be both Default and default Texture Groups in the generated project.

Suggested Fix

Normalize the default Texture Group name during export/decompilation.

For example:

private static string NormalizeTextureGroupName(string name)
{
    if (string.IsNullOrWhiteSpace(name))
        return "Default";

    if (string.Equals(name, "default", StringComparison.OrdinalIgnoreCase))
        return "Default";

    return name;
}

Then use this normalization both when dumping Texture Group definitions and when generating asset references:

name = NormalizeTextureGroupName(texGroup);
path = $"texturegroups/{NormalizeTextureGroupName(texGroup)}";

This should prevent the generated project from containing both Default and default.