Logic parser improvements for quote/escape handling + unit tests

core/src/mindustry/logic/LAssembler.java

@@ -56,22 +56,19 @@ public class LAssembler{
         return new LParser(text, privileged).parse();
     }
 
-    /** @return a variable by name.
-     * This may be a constant variable referring to a number or object. */
+    /**
+     * @return a variable by name. This may be a constant variable referring to a number or object.
+     * @param symbol the string literal, numeric literal, or variable name. Leading or trailing spaces are not allowed.
+     * */
     public LVar var(String symbol){
         LVar constVar = Vars.logicVars.get(symbol, privileged);
         if(constVar != null) return constVar;
 
-        symbol = symbol.trim();
-
         //string case
-        if(!symbol.isEmpty() && symbol.charAt(0) == '\"' && symbol.charAt(symbol.length() - 1) == '\"'){
-            return putConst("___" + symbol, symbol.substring(1, symbol.length() - 1).replace("\\n", "\n"));
+        if(symbol.length() > 1 && symbol.charAt(0) == '\"' && symbol.charAt(symbol.length() - 1) == '\"'){
+            return putConst("___" + symbol, symbol.substring(1, symbol.length() - 1));
         }
 
-        //remove spaces for non-strings
-        symbol = symbol.replace(' ', '_');
-
         //use a positive invalid number if number might be negative, else use a negative invalid number
         double value = parseDouble(symbol);
 

core/src/mindustry/logic/LParser.java

@@ -25,6 +25,11 @@ public class LParser{
     LParser(String text, boolean privileged){
         this.privileged = privileged;
         this.chars = text.toCharArray();
+
+        //normalize CRLF and lone-CR line endings to LF in place; avoids extra allocations, and an extra \n is harmless
+        for(int i = 0; i < chars.length; i++){
+            if(chars[i] == '\r') chars[i] = '\n';
+        }
     }
 
     void comment(){
@@ -39,15 +44,44 @@ public class LParser{
     String string(){
         int from = pos;
         int utflen = 0;
+        //only allocated if an escape sequence is found
+        StringBuilder escaped = null;
 
         while(++pos < chars.length){
             char c = chars[pos];
+
+            //handle \n and \" escape sequences (also \\ so a literal backslash can be written)
+            if(c == '\\' && pos + 1 < chars.length){
+                char translated = switch(chars[pos + 1]){
+                    case 'n' -> '\n';
+                    case '"' -> '"';
+                    case '\\' -> '\\';
+                    default -> 0;
+                };
+
+                if(translated != 0){
+                    if(escaped == null){
+                        //copy everything read so far (without the surrounding quote)
+                        escaped = new StringBuilder();
+                        escaped.append(chars, from + 1, pos - from - 1);
+                    }
+
+                    escaped.append(translated);
+                    utflen += translated <= 0x7F ? 1 : translated <= 0x7FF ? 2 : 3;
+                    pos ++; //consume the escaped character too
+                    continue;
+                }
+                //not a recognized escape sequence; fall through and treat the backslash as a literal character (TODO: isn't this an invalid escape?)
+            }
+
             if(c == '\n'){
                 error("Missing closing quote \" before end of line.");
             }else if(c == '"'){
                 break;
             }
 
+            if(escaped != null) escaped.append(c);
+
             // See ByteBufferOutput.writeUTF()
             utflen += c != 0 && c <= 0x7F ? 1 : c <= 0x7FF ? 2 : 3;
         }
@@ -55,7 +89,13 @@ public class LParser{
         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);
+        pos ++; //move past the closing quote
+
+        if(escaped != null){
+            return "\"" + escaped + "\"";
+        }
+
+        return new String(chars, from, pos - from);
     }
 
     String token(){
@@ -63,7 +103,7 @@ public class LParser{
 
         while(pos < chars.length){
             char c = chars[pos];
-            if(c == '\n' || c == ' ' || c == '#' || c == '\t' || c == ';') break;
+            if(c == '\n' || c == ' ' || c == '#' || c == '\t' || c == ';' || c == '"') break;
             pos ++;
         }
 
@@ -191,7 +231,6 @@ public class LParser{
         while(pos < chars.length && line < LExecutor.maxInstructions){
             switch(chars[pos]){
                 case '\n', ';', ' ' -> pos ++; //skip newlines and spaces
-                case '\r' -> pos += 2; //skip the newline after the \r
                 default -> statement();
             }
         }
@@ -217,4 +256,4 @@ public class LParser{
         }
     }
 
-}
+}

core/src/mindustry/logic/LStatement.java

@@ -83,7 +83,8 @@ public abstract class LStatement{
         tooltip(label, text);
     }
 
-    protected String sanitize(String value){
+    /** Sanitizes variable input strings from text fields into values that will not break logic parsing. */
+    public static String sanitize(String value){
         if(value.length() == 0){
             return "";
         }else if(value.length() == 1){
@@ -94,12 +95,14 @@ public abstract class LStatement{
             StringBuilder res = new StringBuilder(value.length());
             if(value.charAt(0) == '"' && value.charAt(value.length() - 1) == '"'){
                 res.append('\"');
-                //strip out extra quotes
+                //escape characters that would otherwise break out of the string or corrupt it
                 for(int i = 1; i < value.length() - 1; i++){
-                    if(value.charAt(i) == '"'){
-                        res.append('\'');
-                    }else{
-                        res.append(value.charAt(i));
+                    char c = value.charAt(i);
+                    switch(c){
+                        case '"' -> res.append("\\\"");
+                        case '\\' -> res.append("\\\\");
+                        case '\n' -> res.append("\\n");
+                        default -> res.append(c);
                     }
                 }
                 res.append('\"');

core/src/mindustry/logic/LogicDialog.java

@@ -138,7 +138,7 @@ public class LogicDialog extends BaseDialog{
                     t.button("@load.clipboard", Icon.download, style, () -> {
                         dialog.hide();
                         try{
-                            canvas.load(Core.app.getClipboardText().replace("\r\n", "\n"));
+                            canvas.load(Core.app.getClipboardText());
                         }catch(Throwable e){
                             ui.showException(e);
                         }