io: Don't call getcwd in xmlParserGetDirectory

The "directory" value isn't used internally. Calling getcwd is
unnecessary and can cause problems in sandboxed environments.

Fixes #770.

Author: nwellnhof

xmlIO.c

@@ -2904,10 +2904,7 @@ xmlParserGetDirectory(const char *filename) {
 	else *cur = 0;
 	ret = xmlMemStrdup(dir);
     } else {
-        if (getcwd(dir, 1024) != NULL) {
-	    dir[1023] = 0;
-	    ret = xmlMemStrdup(dir);
-	}
+        ret = xmlMemStrdup(".");
     }
     return(ret);
 #undef IS_XMLPGD_SEP