minecraftforge / installertools

A collection of command line tools that are useful for the Forge installer, that are not worth being their own standalone projects.

MinecraftForge

Forge is a free, open-source modding API all of your favourite mods use!

Version	Support
1.20.x	Active
1.19.x	Legacy

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Installing Forge

Go to the Forge website and select the Minecraft version you wish to get Forge for from the list.

You can download the installer for the Recommended Build or the Latest build there. Latest builds may have newer features but may be more unstable as a result. The installer will attempt to install Forge into your vanilla launcher environment, where you can then create a new profile using that version and play the game!

For support and questions, visit the Support Forum or the Forge Discord server.

Creating Mods

See the "Getting Started" section in the Forge Documentation.

Contribute to Forge

If you wish to actually inspect Forge, submit PRs or otherwise work with Forge itself, you're in the right place!

See the guide to setting up a Forge workspace.

Pull requests

See the "Making Changes and Pull Requests" section in the Forge documentation.

Please read the contributing guidelines found here before making a pull request.

Contributor License Agreement

We require all contributors to acknowledge the Forge Contributor License Agreement. Please ensure you have a valid email address associated with your GitHub account to do this. If you have previously signed it, you should be OK.

Donate

Forge is a large project with many collaborators working on it around the clock. Forge is and will always remain free to use and modify. However, it costs money to run such a large project as this, so please consider becoming a patron.

installertools's Issues

Download mojmap do not follow installer's --offline and --debug option

SrgToMcpRenamer uses hardcoded path for nested jars

The Issue

Currently, only nested jars under the META-INF/jarjar/ directory are deobfuscated by SrgToMcpRenamer.

InstallerTools/src/main/java/net/minecraftforge/installertools/SrgMcpRenamer.java

Line 132 in dd66a7d

processors.add(new ZipEntryProcessor(ein -> ein.getName().startsWith("META-INF/jarjar/") && ein.getName().endsWith(".jar"),

While this is the most common folder for nested jars, JarJar metadata defines nested jar paths as paths relative to the outer jar's root, and therefore nested jars can be located anywhere in the jar. This breaks mods that place their nested jars in other paths than the mentioned folder.

Expected behavior

SrgToMcpRenamer is able to deobfuscate any nested jars regardless of their location, as specified by JarJar metadata. Rather than assuming all nested jars are in the META-INF/jarjar/ directory, we should open the jar's JarJar metadata file and read nested jar paths from it.

SrgMcpRenamer may throw "ZipException: invalid entry compressed size"

In SrgMcpRenamer, it is possible for the last case in the zip copying function to throw a ZipException: invalid entry compressed size:

zout.putNextEntry(ein);
Utils.copy(zin, zout);

The stack trace might look like this, which is what I get when I try to use the dependency curse.maven:tinkers-tool-leveling-250957:2630860:

Exception in thread "main" java.util.zip.ZipException: invalid entry compressed size (expected 256 but got 257 bytes)
	at java.util.zip.ZipOutputStream.closeEntry(ZipOutputStream.java:267)
	at java.util.zip.ZipOutputStream.putNextEntry(ZipOutputStream.java:192)
	at net.minecraftforge.installertools.SrgMcpRenamer.process(SrgMcpRenamer.java:155)
	at net.minecraftforge.installertools.ConsoleTool.main(ConsoleTool.java:55)
	Suppressed: java.util.zip.ZipException: invalid entry compressed size (expected 256 but got 257 bytes)
		at java.util.zip.ZipOutputStream.closeEntry(ZipOutputStream.java:267)
		at java.util.zip.ZipOutputStream.finish(ZipOutputStream.java:360)
		at java.util.zip.DeflaterOutputStream.close(DeflaterOutputStream.java:238)
		at java.util.zip.ZipOutputStream.close(ZipOutputStream.java:377)
		at net.minecraftforge.installertools.SrgMcpRenamer.process(SrgMcpRenamer.java:159)
		... 1 more

This happens because it's possible for slight discrepancies to arise between the compressed size of a file in the original archive and the mapped one, but since the code just straight up copies over the exact same ZipEntry instance, the discrepancy is noticed by ZipOutputStream, which assumes it's an error and raises this exception. A fix might be simply to create a new ZipEntry (as is done in the other cases) and to populate all the fields manually, so the new compressed size is computed automatically.