Program: 58401
Project: 58401
Buggy source:
private static byte[] alterController(String name,String transformedName,byte[] bytes,ClassReader cr){
  String[] names;
  if (LoadingPlugin.runtimeDeobfEnabled) {
    names=new String[]{"String_Node_Str","String_Node_Str"};
  }
 else {
    names=new String[]{"String_Node_Str","String_Node_Str"};
  }
  name=name.replace('.','/');
  ClassNode cn=new ClassNode(ASM5);
  cr.accept(cn,ClassReader.EXPAND_FRAMES);
  final String sig="String_Node_Str";
  final String itemstack="String_Node_Str";
  l: {
    MethodNode m=null;
    for (    MethodNode n : cn.methods) {
      if (names[0].equals(n.name) && sig.equals(n.desc)) {
        m=n;
        break;
      }
    }
    if (m == null) {
      break l;
    }
    for (int i=0, e=m.instructions.size(); i < e; i++) {
      AbstractInsnNode n=m.instructions.get(i);
      if (n.getOpcode() == INVOKEVIRTUAL) {
        MethodInsnNode mn=(MethodInsnNode)n;
        if (itemstack.equals(mn.owner)) {
          LabelNode jmp=null, jmp2=null;
          s:           for (int j=i; j < e; ++j) {
            n=m.instructions.get(j);
            if (n.getOpcode() == ICONST_1) {
              for (int k=j; k > i; --k) {
                n=m.instructions.get(k);
                if (n.getType() == AbstractInsnNode.LABEL) {
                  jmp=(LabelNode)n;
                  break;
                }
              }
              for (int k=j; k < e; ++k) {
                n=m.instructions.get(k);
                if (n.getType() == AbstractInsnNode.LABEL) {
                  jmp2=(LabelNode)n;
                  break s;
                }
              }
            }
          }
          if (jmp == null || jmp2 == null) {
            break l;
          }
          m.instructions.insertBefore(mn,new VarInsnNode(ALOAD,0));
          m.instructions.insertBefore(mn,new FieldInsnNode(GETFIELD,name,names[1],'L' + itemstack + ';'));
          final String clazz="String_Node_Str";
          final String method="String_Node_Str";
          final String sign="String_Node_Str";
          m.instructions.insertBefore(mn,new MethodInsnNode(INVOKESTATIC,clazz,method,sign,false));
          m.instructions.insertBefore(mn,new JumpInsnNode(IFEQ,jmp2));
          m.instructions.insertBefore(mn,new JumpInsnNode(GOTO,jmp));
          break;
        }
      }
    }
    ClassWriter cw=new ClassWriter(ClassWriter.COMPUTE_MAXS);
    cn.accept(cw);
    bytes=cw.toByteArray();
  }
  return bytes;
}

Fixed version (ground truth):
private static byte[] alterController(String name,String transformedName,byte[] bytes,ClassReader cr){
  String[] names;
  if (LoadingPlugin.runtimeDeobfEnabled) {
    names=new String[]{"String_Node_Str","String_Node_Str"};
  }
 else {
    names=new String[]{"String_Node_Str","String_Node_Str"};
  }
  name=transformedName.replace('.','/');
  ClassNode cn=new ClassNode(ASM5);
  cr.accept(cn,ClassReader.EXPAND_FRAMES);
  final String sig="String_Node_Str";
  final String itemstack="String_Node_Str";
  l: {
    MethodNode m=null;
    for (    MethodNode n : cn.methods) {
      if (names[0].equals(n.name) && sig.equals(n.desc)) {
        m=n;
        break;
      }
    }
    if (m == null) {
      break l;
    }
    for (int i=0, e=m.instructions.size(); i < e; i++) {
      AbstractInsnNode n=m.instructions.get(i);
      if (n.getOpcode() == INVOKEVIRTUAL) {
        MethodInsnNode mn=(MethodInsnNode)n;
        if (itemstack.equals(mn.owner)) {
          LabelNode jmp=null, jmp2=null;
          s:           for (int j=i; j < e; ++j) {
            n=m.instructions.get(j);
            if (n.getOpcode() == ICONST_1) {
              for (int k=j; k > i; --k) {
                n=m.instructions.get(k);
                if (n.getType() == AbstractInsnNode.LABEL) {
                  jmp=(LabelNode)n;
                  break;
                }
              }
              for (int k=j; k < e; ++k) {
                n=m.instructions.get(k);
                if (n.getType() == AbstractInsnNode.LABEL) {
                  jmp2=(LabelNode)n;
                  break s;
                }
              }
            }
          }
          if (jmp == null || jmp2 == null) {
            break l;
          }
          m.instructions.insertBefore(mn,new VarInsnNode(ALOAD,0));
          m.instructions.insertBefore(mn,new FieldInsnNode(GETFIELD,name,names[1],'L' + itemstack + ';'));
          final String clazz="String_Node_Str";
          final String method="String_Node_Str";
          final String sign="String_Node_Str";
          m.instructions.insertBefore(mn,new MethodInsnNode(INVOKESTATIC,clazz,method,sign,false));
          m.instructions.insertBefore(mn,new JumpInsnNode(IFEQ,jmp2));
          m.instructions.insertBefore(mn,new JumpInsnNode(GOTO,jmp));
          break;
        }
      }
    }
    ClassWriter cw=new ClassWriter(ClassWriter.COMPUTE_MAXS);
    cn.accept(cw);
    bytes=cw.toByteArray();
  }
  return bytes;
}