5.0 fixes / changes

[alkrun]

I figured I'd make one thread for things I fix / change, this was just the first significant change. If I understood what calc() was supposed to do in parser.cpp (that is, calculate a simple math expression in a string) then it had a few problems. I rewrote it, see below:

int calc( string calc )
{
	string::iterator iterator = calc.begin();
	string buffer;
	string integer1;
	char op = 0;
	int returnvalue = 0;
	
	while (*iterator)
	{
		char ch = *iterator;
		
		if(ch >= '0' && ch <= '9')//If this character is numeric add it to the buffer
		{
			buffer += ch;
		}
		else if(ch == '+' || ch == '-' || ch == '/' || ch == '*')//otherwise, are we an operator?
		{
			int val = atoi(buffer.c_str());
			if(!op)//if this is the first time through, set returnvalue to what we have so far
			{
				returnvalue = val;
			}
			else//otherwise we've got returnvalue initialized, perform operation on previous numbers
			{
				if(buffer.length() == 0)//Do we have a value?
				{
					printf("Parser::calc() Error in syntax: '%s'.\n", calc);
					return 0;
				}
				//what was the previous op
				switch(op)
				{
				case '+':
					{
						returnvalue += val;
						break;
					}
				case '-':
					{
						returnvalue -= val;
						break;
					}
				case '/':
					{
						if(val == 0)//can't divide by zero
						{
							printf("Parser::calc() Error, Divide by zero '%s'.\n", calc);
							return 0;
						}
						returnvalue /= val;
						break;
					}
				case '*':
					{
						returnvalue *= val;
						break;
					}
				};
				op = ch;//save current operator and continue parsing
				buffer.clear();//clear buffer now that we're starting on a new number
			}
			op = ch;
		}
		else
		{
			printf("Parser::calc() Error processing '%c'.\n", ch);
			return 0;
		}
	}
	return returnvalue;
}