osutil: stop using strcpy

strcpy is a security vulnerability masquerading as a utility
function. Replace it with memcpy since we know how much to copy
anyway.

mercurial/osutil.c

@@ -203,14 +203,15 b' static PyObject *_listdir(char *path, in'
 		PyErr_NoMemory();
 		goto error_nomem;
 	}
-	strcpy(pattern, path);
+	memcpy(pattern, path, plen);
 
 	if (plen > 0) {
 		char c = path[plen-1];
 		if (c != ':' && c != '/' && c != '\\')
 			pattern[plen++] = '\\';
 	}
-	strcpy(pattern + plen, "*");
+	pattern[plen++] = '*';
+	pattern[plen] = '\0';
 
 	fh = FindFirstFileA(pattern, &fd);
 	if (fh == INVALID_HANDLE_VALUE) {