<bad ptr> Overloading + Operator

Question

The debugger is giving me 'bad ptr' when I create a new string array in this constructor, but only when my overloading operator method creates a new MyString object... confused.

Here is my constructor

MyString::MyString()
{
     stringSize = 0;
     stringCap = 16;
     stringArray = new char[stringCap + 1];
     stringArray[0] = '\0';
}

Here is my overloading operator method

MyString operator+(const char* leftOp, const MyString& rightOp)
{
     MyString result; // new object used to store result
     result.stringSize = strlen(leftOp) + rightOp.stringSize;
     // if the string does not fit in the array
     if( result.stringSize > result.stringCap )
     {
         delete[] result.stringArray;
         result.stringCap = ( result.stringSize + 15 ) & ~15;
         result.stringArray = new char[result.stringCap + 1];
     }
     strcpy(result.stringArray, leftOp);
     strcat(result.stringArray, rightOp.stringArray);
     return result;
  }

Here is my copy constructor, which the debugger never gets too

MyString::MyString(const MyString& s)
{
    stringSize = s.stringSize;
    stringCap = s.stringCap;
    //stringArray[stringCap + 1];
    stringArray = new char[stringCap + 1];
    stringArray = s.stringArray;
}

Answer 1

Well, when this method returns, "result" is going to be copied and the original destructed. If the destructor deletes the array, and there isn't a smart copy constructor which ensures that the new copy includes a valid new array, then you're going to have problems.

But you said the compiler says something about a bad pointer -- where? What line?

Answer 2

Since from your code snippet, nothing seems wrong, my sixth sense tells me that you've NOT written copy-constructor, and are working with the default one generated by the compiler, or possibly stringArray is not a null-terminated string!

EDIT:

In your copy-constructor, this is wrong:

stringArray = s.stringArray; //wrong!

Use strcpy instead:

strcpy(stringArray, s.stringArray); //correct!

Make sure all your strings are null-terminated!