coral_survive.js

function initializeCoreMod() {
    return {
        'CoralWaterPatch': {
            'target': {
                'type': 'METHOD',
                'class': 'net/minecraft/block/CoralBlock',
                'methodName': 'method_9431',
                'methodDesc': '(Lnet/minecraft/world/IBlockReader;Lnet/minecraft/util/math/BlockPos;)Z'
            },
            'transformer': function(methodNode) {
                var Opcodes = Java.type('org.objectweb.asm.Opcodes');
                var ASMAPI = Java.type('net.minecraftforge.coremod.api.ASMAPI');
                var LabelNode = Java.type('org.objectweb.asm.tree.LabelNode');
                var InsnNode = Java.type('org.objectweb.asm.tree.InsnNode');
                var VarInsnNode = Java.type('org.objectweb.asm.tree.VarInsnNode');
                var MethodInsnNode = Java.type('org.objectweb.asm.tree.MethodInsnNode');
                var JumpInsnNode = Java.type('org.objectweb.asm.tree.JumpInsnNode');
                var TypeInsnNode = Java.type('org.objectweb.asm.tree.TypeInsnNode');

                var instructions = methodNode.instructions;
                var isCall = ASMAPI.findFirstMethodCall(
                    methodNode,
                    ASMAPI.MethodType.VIRTUAL,
                    'net/minecraft/fluid/FluidState',
                    ASMAPI.mapMethod('method_15767'),
                    '(Lnet/minecraft/tags/ITag)Z;'
                );

                var isCallIndex = instructions.indexOf(isCall);
                var firstLabelBeforeIsCall = findFirstLabelBeforeIndex(instructions, isCallIndex);
                var END = new LabelNode();
                var AFTER_RETURN = new LabelNode();
                var L1 = findFirstLabel(instructions, 1);
                instructions.insert(firstLabelBeforeIsCall, ASMAPI.listOf(
                    new VarInsnNode(Opcodes.ALOAD, 5), // fluidstate
                    new MethodInsnNode(
                        Opcodes.INVOKVIRTUAL,
                        'net/minecraft/fluid/FluidState',
                        ASMAPI.mapMethod('method_15769'),
                        '()Z',
                        false
                    ),
                    new JumpInsnNode(Opcodes.IFNE, AFTER_RETURN),
                    new VarInsnNode(Opcodes.ALOAD, 5), // fluidstate
                    new MethodInsnNode(
                        Opcodes.INVOKEVIRTUAL,
                        'net/minecraft/fluid/FluidState',
                        ASMAPI.mapMethod('method_15772'), // getType
                        '()Lnet/minecraft/fluid/Fluid;',
                        false
                    ),
                    new TypeInsnNode(
                        Opcodes.INSTANCEOF,
                        'io/github/darealturtywurty/fluidfixes/common/FixedFluid'
                    ),
                    new JumpInsnNode(Opcodes.IFEQ, END),

                    new FieldInsnNode(
                        Opcodes.GETSTATIC,
                        'java/lang/System',
                        'out',
                        'Ljava/io/PrintStream;'
                    ),
                    new VarInsnNode(Opcodes.ALOAD, 5), // fluidstate
                    new MethodInsnNode(
                        Opcodes.INVOKE_VIRTUAL,
                        'java/io/PrintStream',
                        'println',
                        '(Ljava/lang/Object;)V',
                        false
                    ),
                    new VarInsnNode(Opcodes.ALOAD, 5), // fluidstate
                    new MethodInsnNode(
                        Opcodes.INVOKEVIRTUAL,
                        'net/minecraft/fluid/FluidState',
                        ASMAPI.mapMethod('method_15772'), // getType
                        '()Lnet/minecraft/world/level/material/Fluid;',
                        false
                    ),
                    new TypeInsnNode(Opcodes.CHECKCAST, 'io/github/darealturtywurty/fluidfixes/common/FixedFluid'),
                    new MethodInsnNode(
                        Opcodes.INVOKEVIRTUAL,
                        'io/github/darealturtywurty/fluidfixes/common/FixedFluid',
                        'isCanCoralsSurvive',
                        '()Z',
                        false
                    ),
                    new JumpInsnNode(Opcodes.IFEQ, AFTER_RETURN),

                    new InsnNode(Opcodes.ICONST_1),
                    new InsnNode(Opcodes.IRETURN),

                    AFTER_RETURN,
                    new JumpInsnNode(Opcodes.GOTO, L1),

                    END
                ));
                return methodNode;
            }
        }
    }
}

// Credits Cadiboo
function findFirstLabelBeforeIndex(instructions, startIndex) {
    var length = instructions.size();
    if (!startIndex)
        startIndex = length - 1;
    var i;
    for (i = startIndex; i >= 0; --i) {
        var instruction = instructions.get(i);
        if (instruction.getType() == LABEL) {
            print('Found first label before index ' + startIndex + ': ' + instruction);
            return instruction;
        }
    }
    throw new Error("Error: Couldn't find first label before index " + startIndex);
}

// Credits Cadiboo
function findFirstLabel(instructions, startIndex) {
    if (!startIndex)
        startIndex = 0;
    var length = instructions.size();
    var i;
    for (i = startIndex; i < length; ++i) {
        var instruction = instructions.get(i);
        if (instruction.getType() == LABEL) {
            print('Found second label after index ' + startIndex + ': ' + instruction);
            return instruction;
        }
    }
    throw new Error("Error: Couldn't find first label after index " + startIndex + ' in ' + instructions);
}