Program: 83871
Project: 83871
Buggy source:
@Override public int getSignatureMatch(String name,IValue instance,IArguments arguments){
  if (name == null) {
    return 1;
  }
  if (!name.equals(this.qualifiedName)) {
    return 0;
  }
  if (arguments == null) {
    return 1;
  }
  int pOff=0;
  int match=1;
  int len=arguments.size();
  int mods=this.modifiers & Modifiers.INFIX;
  if (instance != null && mods == Modifiers.INFIX) {
    if (len != this.parameterCount - 1) {
      return 0;
    }
    IType t2=this.parameters[0].type;
    int m=instance.getTypeMatch(t2);
    if (m == 0) {
      return 0;
    }
    match+=m;
    pOff=1;
  }
 else   if (mods == Modifiers.STATIC && instance != null && instance.getValueType() != IValue.CLASS_ACCESS) {
    return 0;
  }
 else   if ((this.modifiers & Modifiers.VARARGS) != 0) {
    int parCount=this.parameterCount - 1;
    if (len <= parCount) {
      return 0;
    }
    int m;
    Parameter varParam=this.parameters[parCount];
    varParam.index=parCount;
    for (int i=0; i < parCount; i++) {
      Parameter par=this.parameters[i + pOff];
      par.index=i + pOff;
      m=arguments.getTypeMatch(par);
      if (m == 0) {
        return 0;
      }
      match+=m;
    }
    for (int i=parCount; i < len; i++) {
      m=arguments.getVarargsTypeMatch(varParam);
      if (m == 0) {
        return 0;
      }
      match+=m;
    }
    return match;
  }
 else   if (len > this.parameterCount) {
    return 0;
  }
  for (int i=0; i < this.parameterCount; i++) {
    Parameter par=this.parameters[i + pOff];
    par.index=i;
    int m=arguments.getTypeMatch(par);
    if (m == 0) {
      return 0;
    }
    match+=m;
  }
  return match;
}

Fixed version (ground truth):
@Override public int getSignatureMatch(String name,IValue instance,IArguments arguments){
  if (name != null && !name.equals(this.qualifiedName)) {
    return 0;
  }
  if (arguments == null) {
    return 1;
  }
  int pOff=0;
  int match=1;
  int len=arguments.size();
  int mods=this.modifiers & Modifiers.INFIX;
  if (instance != null && mods == Modifiers.INFIX) {
    if (len != this.parameterCount - 1) {
      return 0;
    }
    IType t2=this.parameters[0].type;
    int m=instance.getTypeMatch(t2);
    if (m == 0) {
      return 0;
    }
    match+=m;
    pOff=1;
  }
 else   if (mods == Modifiers.STATIC && instance != null && instance.getValueType() != IValue.CLASS_ACCESS) {
    return 0;
  }
 else   if ((this.modifiers & Modifiers.VARARGS) != 0) {
    int parCount=this.parameterCount - 1;
    if (len <= parCount) {
      return 0;
    }
    int m;
    Parameter varParam=this.parameters[parCount];
    varParam.index=parCount;
    for (int i=0; i < parCount; i++) {
      Parameter par=this.parameters[i + pOff];
      par.index=i + pOff;
      m=arguments.getTypeMatch(par);
      if (m == 0) {
        return 0;
      }
      match+=m;
    }
    for (int i=parCount; i < len; i++) {
      m=arguments.getVarargsTypeMatch(varParam);
      if (m == 0) {
        return 0;
      }
      match+=m;
    }
    return match;
  }
 else   if (len > this.parameterCount) {
    return 0;
  }
  for (int i=0; i < this.parameterCount; i++) {
    Parameter par=this.parameters[i + pOff];
    par.index=i;
    int m=arguments.getTypeMatch(par);
    if (m == 0) {
      return 0;
    }
    match+=m;
  }
  return match;
}