Gracefully handle string value size exceeding 65535 bytes (#11750)

core/src/mindustry/logic/LParser.java

@@ -37,17 +37,22 @@ public class LParser{
 
     String string(){
         int from = pos;
+        int utflen = 0;
 
         while(++pos < chars.length){
-            var c = chars[pos];
+            char c = chars[pos];
             if(c == '\n'){
                 error("Missing closing quote \" before end of line.");
             }else if(c == '"'){
                 break;
             }
+
+            // See ByteBufferOutput.writeUTF()
+            utflen += c != 0 && c <= 0x7F ? 1 : c <= 0x7FF ? 2 : 3;
         }
 
         if(pos >= chars.length || chars[pos] != '"') error("Missing closing quote \" before end of file.");
+        if(utflen > 65535) error("String value too long.");
 
         return new String(chars, from, ++pos - from);
     }