File not found using relative path and classpath type

Issue details

relative path doesn’t work with classpath type. It works well with internal type but not when assets are in the final jar.

Reproduction steps/code

load a skin containing a bitmap font with relative path :

{
com.badlogic.gdx.graphics.g2d.BitmapFont: { 
	default-font: { file: ../fonts/game_font.fnt } 
}

Note : it will works for desktop when files are in an external folder but fails when files are inside the dist jar (loaded from classpath)

Version of LibGDX and/or relevant dependencies

1.9.6 with Lwjgl2 backend

Stacktrace

Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: com.badlogic.gdx.utils.SerializationException: Error reading file: skins/game-skin.json
	at com.badlogic.gdx.assets.AssetManager.handleTaskError(AssetManager.java:579)
	at com.badlogic.gdx.assets.AssetManager.update(AssetManager.java:380)
	at com.badlogic.gdx.assets.AssetManager.finishLoadingAsset(AssetManager.java:411)
	at net.mgsx.game.core.storage.EntityGroupStorage.loadNow(EntityGroupStorage.java:187)
	at net.mgsx.game.core.storage.EntityGroupStorage.loadForEditing(EntityGroupStorage.java:86)
	at net.mgsx.game.core.EditorApplication.loadWork(EditorApplication.java:113)
	at net.mgsx.game.core.EditorApplication.restoreWork(EditorApplication.java:98)
	at net.mgsx.game.core.EditorApplication.create(EditorApplication.java:59)
	at net.mgsx.examples.platformer.OpenWorldEditorLauncher$1.create(OpenWorldEditorLauncher.java:59)
	at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:149)
	at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:126)
Caused by: com.badlogic.gdx.utils.SerializationException: Error reading file: skins/game-skin.json
	at com.badlogic.gdx.scenes.scene2d.ui.Skin.load(Skin.java:98)
	at com.badlogic.gdx.assets.loaders.SkinLoader.loadSync(SkinLoader.java:75)
	at com.badlogic.gdx.assets.loaders.SkinLoader.loadSync(SkinLoader.java:38)
	at com.badlogic.gdx.assets.AssetLoadingTask.handleAsyncLoader(AssetLoadingTask.java:141)
	at com.badlogic.gdx.assets.AssetLoadingTask.update(AssetLoadingTask.java:90)
	at com.badlogic.gdx.assets.AssetManager.updateTask(AssetManager.java:504)
	at com.badlogic.gdx.assets.AssetManager.update(AssetManager.java:378)
	... 9 more
Caused by: com.badlogic.gdx.utils.SerializationException: Error reading file: skins/game-skin.json
	at com.badlogic.gdx.utils.Json.fromJson(Json.java:702)
	at com.badlogic.gdx.scenes.scene2d.ui.Skin.load(Skin.java:96)
	... 15 more
Caused by: com.badlogic.gdx.utils.SerializationException: Font file not found: ../fonts/game_font.fnt
	at com.badlogic.gdx.scenes.scene2d.ui.Skin$3.read(Skin.java:472)
	at com.badlogic.gdx.scenes.scene2d.ui.Skin$3.read(Skin.java:463)
	at com.badlogic.gdx.utils.Json.readValue(Json.java:892)
	at com.badlogic.gdx.scenes.scene2d.ui.Skin$1.readValue(Skin.java:428)
	at com.badlogic.gdx.utils.Json.readValue(Json.java:860)
	at com.badlogic.gdx.scenes.scene2d.ui.Skin$2.readNamedObjects(Skin.java:449)
	at com.badlogic.gdx.scenes.scene2d.ui.Skin$2.read(Skin.java:438)
	at com.badlogic.gdx.scenes.scene2d.ui.Skin$2.read(Skin.java:434)
	at com.badlogic.gdx.utils.Json.readValue(Json.java:892)
	at com.badlogic.gdx.scenes.scene2d.ui.Skin$1.readValue(Skin.java:428)
	at com.badlogic.gdx.utils.Json.fromJson(Json.java:700)
	... 16 more

Please select the affected platforms

• Android
• iOS (robovm)
• iOS (MOE)
• HTML/GWT
• Windows
• Linux
• MacOS

[mgsx-dev]

After few discussions on Discord, i will close this issue. There is no simple way to fix this, actually more than FileHandle would be impacted : AssetManager rely on String path names and some loaders (TMX Map Loader) resolve relative path internally. A quick fix could be to do the same thing when loading a skin but it may have other impacts. So in the end i don’t think it worth it.

[MrStahlfelge]

If I understand correctly, the FileHandle is instanitated with FileHandle("skins/../fonts/game_font.fnt") here. If this is the case, I think this should be fixed - or better: resolved) right in the constructor.

For GWT, there’s already a fixSlashes method called with a similar intention, but not dealing dealing with double dots.

Path normalization with Apache 2 license can be found here. Some of this is not needed, but there’s a loop dealing with doubler dots.