DMD 1.004 release

[Jordan Miner]

Here is a problem I've found in post-1.00 versions.
I have this unittest in my library:

unittest {
	char[] c = "Computer";
	ArrayCopy!(char)(c, 3, c, 2, 4);
	assert(c == "Coputeer");
	c = "Computer";
	ArrayCopy!(char)(c, 2, c, 3, 4);
	assert(c == "Commputr");
}

I have not changed the ArrayCopy function for months and when I updated from 1.00, the second assert started failing. After some work, I tracked down the problem.
This line:
	c = "Computer";
is not doing anything. I put printf(c) right after that assignment, and it prints "Coputeer".
I didn't test 1.002, but it is broken in 1.001, 1.003, and 1.004.
(I love built-in unittests)



The ArrayCopy function:

void ArrayCopy(T)(T[] srcData, uint srcStart, T[] destData, uint destStart, uint length) {
	if((srcData is destData && srcStart == destStart) || length == 0)
		return;
	if(srcStart > destStart) {
		//copy forward
		for(int i = 0; i < length; ++i)
		  destData[destStart + i] = srcData[srcStart + i];
	} else {
		//copy reverse
		for(int i = length-1; i >= 0; --i)
			destData[destStart + i] = srcData[srcStart + i];
	}
}