view Python/memmove.c @ 17405:afbb65b60fa2 2.0

Inspired by Tim Peters' 1.14->1.15 checkin to asynchat Quoting orignal message: ''' Fix from the Madusa mailing list: http://groups.yahoo.com/group/medusa/message/333 It's clear that Medusa should not be checking for an empty buffer via "buf is ''". The patch merely changes "is" to "==". However, there's a mystery here all the same: Python attempts to store null strings uniquely, so it's unclear why "buf is ''" ever returned false when buf actually was empty. *Some* string operations produce non-unique null strings, e.g. '''
author Moshe Zadka <moshez@math.huji.ac.il>
date Wed, 11 Apr 2001 08:06:02 +0000
parents 6f6f965c5e2d
children
line wrap: on
line source


/* A perhaps slow but I hope correct implementation of memmove */

extern char *memcpy(char *, char *, int);

char *
memmove(char *dst, char *src, int n)
{
	char *realdst = dst;
	if (n <= 0)
		return dst;
	if (src >= dst+n || dst >= src+n)
		return memcpy(dst, src, n);
	if (src > dst) {
		while (--n >= 0)
			*dst++ = *src++;
	}
	else if (src < dst) {
		src += n;
		dst += n;
		while (--n >= 0)
			*--dst = *--src;
	}
	return realdst;
}