Targeting correct instance method call, but AP warns about method from a default interface

[gabizou]

So, for the provided method from AbstractSpawner:

    private boolean isActivated() {
        BlockPos lvt_1_1_ = this.getSpawnerPosition();
        return this.getWorld().isPlayerWithin((double)lvt_1_1_.getX() + 0.5D, (double)lvt_1_1_.getY() + 0.5D, (double)lvt_1_1_.getZ() + 0.5D, (double)this.activatingRangeFromPlayer);
    }

with the provided Mixin:

    @Redirect(method = "isActivated()Z",
        at = @At(value = "INVOKE",
            target = "Lnet/minecraft/world/World;isPlayerWithin(DDDD)Z"))
    public boolean onIsPlayerWithin(final World world, final double x, final double y, final double z, final double distance) {
        // some special handling with sponge
        return false;
    }

We get the following error from the AP:

/Volumes/Dev/Tools/Sponge/1.14/SpongeCommon/src/mixins/java/org/spongepowered/common/mixin/core/world/spawner/AbstractSpawnerMixin.java:95: warning: Cannot find method mapping for @At(INVOKE.<target>) 'Lnet/minecraft/world/World;isPlayerWithin(DDDD)Z'

Which of course provides the following refmap:

    "org/spongepowered/common/mixin/core/world/spawner/AbstractSpawnerMixin": {
      "isActivated()Z": "Lnet/minecraft/world/spawner/AbstractSpawner;func_98279_f()Z"
    },

And this is because, the method is defined in the interface net/minecraft/world/IEntityReader, but on changing this to IEntityReader, as it's suggesting (somewhat), we'll have some nice AP obf mapping:

    "org/spongepowered/common/mixin/core/world/spawner/AbstractSpawnerMixin": {
      "Lnet/minecraft/world/IEntityReader;isPlayerWithin(DDDD)Z": "Lnet/minecraft/world/IEntityReader;func_217358_a(DDDD)Z",
      "isActivated()Z": "Lnet/minecraft/world/spawner/AbstractSpawner;func_98279_f()Z"
    },

HOWEVER, mixin application will fail in production, because the matching bytecode (remapped to srg named, but not decompiled and recompiled) looks like this:

     private func_98279_f() { //()Z
         <localVar:index=0 , name=this , desc=Lnet/minecraft/world/spawner/AbstractSpawner;, sig=null, start=L1, end=L2>
         <localVar:index=1 , name=☃ , desc=Lnet/minecraft/util/math/BlockPos;, sig=null, start=L3, end=L2>

         L1 {
             aload0 // reference to self
             invokevirtual net/minecraft/world/spawner/AbstractSpawner.func_177221_b()Lnet/minecraft/util/math/BlockPos;
             astore1
         }
         L3 {
             aload0 // reference to self
             invokevirtual net/minecraft/world/spawner/AbstractSpawner.func_98271_a()Lnet/minecraft/world/World;
             aload1
             invokevirtual net/minecraft/util/math/BlockPos.func_177958_n()I
             i2d
             ldc 0.5 (java.lang.Double)
             dadd
             aload1
             invokevirtual net/minecraft/util/math/BlockPos.func_177956_o()I
             i2d
             ldc 0.5 (java.lang.Double)
             dadd
             aload1
             invokevirtual net/minecraft/util/math/BlockPos.func_177952_p()I
             i2d
             ldc 0.5 (java.lang.Double)
             dadd
             aload0 // reference to self
             getfield net/minecraft/world/spawner/AbstractSpawner.field_98289_l:int
             i2d
             invokevirtual net/minecraft/world/World.func_217358_a(DDDD)Z
             ireturn
         }
         L2 {
         }
     }

Note the last invokevirtual net/minecraft/world/World.func_217358_a(DDDD)Z and it is not IEntityReader.func_217358_a(DDDD)Z, even though in theory this should be fine (relatively speaking, its an invokeinterface, but there's likely some proguard shenanigans at play here with relation to calling default implemented methods).

[Mumfrey]

I couldn't figure out why 9438945 didn't auto-close this and then I realised I put the hash in front of Fixed instead of in front of 438. I'm an idiot. This is fixed.