In samba 2.2.8a and 3.0.1rc1, 
smbd/vfs-wrap.c/vfswrap_rename() call rename() and evaluate errno value without 
checking return value of rename().

I think correct condition is "result != 0 && errno == EXDEV".

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int vfswrap_rename(...)
{
	int result;

	START_PROFILE(syscall_rename);
	result = rename(old, new);
	if (errno == EXDEV) {
         ^^^^^^^^^^^^^^^^^^^^^^
		/* Rename across filesystems needed. */
		result = copy_reg(old, new);
	}

	END_PROFILE(syscall_rename);
	return result;
}
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