[Loyto-SKHR]

Problem

With agent 2.1.0, no Bukkit plugin loads on MCPC+ 1.6.4. Every plugin fails with:

Could not load 'plugins/WorldEdit.jar' in folder 'plugins'
org.bukkit.plugin.InvalidPluginException: java.lang.ClassNotFoundException: Failed to remap class com.sk89q.worldedit.bukkit.WorldEditPlugin
Caused by: java.lang.NoSuchMethodError: 'java.lang.String org.objectweb.asm.commons.Remapper.mapFieldName(java.lang.String, java.lang.String, java.lang.String, int)'
    at net.md_5.specialsource.RemappingClassAdapter.visitField(RemappingClassAdapter.java:125)

MCPC+ remaps every plugin class with its bundled SpecialSource, which calls
Remapper.mapFieldName and Remapper.mapMethodName with a fourth argument (the
member's access flags). MCPC+'s ASM 4 had these overloads; stock ASM 9 does not.
Plugins depending on a failed one (e.g. anything needing WorldEdit) are then skipped too.

Fix

In patchAsm, the bundled Remapper gets the two overloads back, as MCPC+'s ASM 4 had them:

• mapFieldName(owner, name, desc) / mapMethodName(owner, name, desc) call the
  4 argument version with access = 0;
• the new mapFieldName(owner, name, desc, int) / mapMethodName(owner, name, desc, int)
  return the name unchanged.

SpecialSource's JarRemapper overrides the 4 argument methods, so plugin classes are
remapped whichever overload ASM or SpecialSource calls. The patch fails the build if
the methods are missing or already present, like the other ASM patches.

Only build.gradle changes.

Testing

• Scanned every ASM reference in the MCPC+ 1.6.4 server jar against the bundled ASM 9.7:
  these two overloads were the only missing members.
• Remapped a test class with MCPC+'s JarRemapper: the original bundled ASM reproduces
  the NoSuchMethodError, the patched Remapper renames the class, field and method correctly.