Made multiline string literals ignore an initial newline.

frog/leg/string_validator.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Check the validity of string literals.
 
 #library("stringvalidator");
 
 #import("leg.dart");
 #import("scanner/scannerlib.dart");
@@ skipping 29 matching lines @@
     SourceString content = source.copyWithoutQuotes(leftQuote, rightQuote);
     return validateString(token,
                           token.charOffset + leftQuote,
                           content,
                           quoting);
   }
 
   static StringQuoting quotingFromString(SourceString sourceString) {
     Iterator<int> source = sourceString.iterator();
     bool raw = false;
+    int quoteLength = 1;
     int quoteChar = source.next();
     if (quoteChar == $AT) {
       raw = true;
       quoteChar = source.next();
     }
     assert(quoteChar === $SQ || quoteChar === $DQ);
     // String has at least one quote. Check it if has three.
     // If it only have two, the string must be an empty string literal,
     // and end after the second quote.
     bool multiline = false;
-    if (source.hasNext() && source.next() == quoteChar && source.hasNext()) {
-      assert(source.next() == quoteChar);
-      multiline = true;
+    if (source.hasNext() && source.next() === quoteChar && source.hasNext()) {
+      int code = source.next();
+      assert(code === quoteChar);  // If not, there is a bug in the parser.
+      quoteLength = 3;
+      // Check if a multiline string starts with a newline (CR, LF or CR+LF).
+      if (source.hasNext()) {
+        code = source.next();
+        if (code === $CR) {
+          quoteLength += 1;
+          if (source.hasNext() && source.next() === $LF) {
+            quoteLength += 1;
+          }
+        } else if (code === $LF) {
+          quoteLength += 1;
+        }
+      }
     }
-    return StringQuoting.get(quoteChar, raw, multiline);
+    return StringQuoting.get(quoteChar, raw, quoteLength);
   }
 
   void stringParseError(String message, Token token, int offset) {
     listener.cancel("$message @ $offset", token : token);
   }
 
   /**
    * Validates the escape sequences and special characters of a string literal.
    * Returns a DartString if valid, and null if not.
    */
@@ skipping 89 matching lines @@
       }
     }
     // String literal successfully validated.
     if (quoting.raw || !containsEscape) {
       // A string without escapes could just as well have been raw.
       return new DartString.rawString(string, length);
     }
     return new DartString.escapedString(string, length);
   }
 }