Fix bug with percent formats with no integer part

lib/src/intl/number_format.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.
 
 part of intl;
 /**
  * Provides the ability to format a number in a locale-specific way. The
  * format is specified as a pattern using a subset of the ICU formatting
  * patterns.
  *
@@ skipping 292 matching lines @@
       }
       // Separate out the extra integer parts from the fraction part.
       extraIntegerDigits = remainingDigits ~/ power;
       fractionPart = remainingDigits % power;
     }
     var fractionPresent = minimumFractionDigits > 0 || fractionPart > 0;
 
     var integerDigits = _integerDigits(integerPart, extraIntegerDigits);
     var digitLength = integerDigits.length;
 
-    if (_hasPrintableIntegerPart(integerPart)) {
+    if (_hasIntegerDigits(integerDigits)) {
       _pad(minimumIntegerDigits - digitLength);
       for (var i = 0; i < digitLength; i++) {
         _addDigit(integerDigits.codeUnitAt(i));
         _group(digitLength, i);
       }
     } else if (!fractionPresent) {
       // If neither fraction nor integer part exists, just print zero.
       _addZero();
     }
 
@@ skipping 55 matching lines @@
 
   /** Print the decimal separator if appropriate. */
   void _decimalSeparator(bool fractionPresent) {
     if (_decimalSeparatorAlwaysShown || fractionPresent) {
       _add(symbols.DECIMAL_SEP);
     }
   }
 
   /**
    * Return true if we have a main integer part which is printable, either
-   * because we have digits left of the decimal point, or because there are
-   * a minimum number of printable digits greater than 1.
+   * because we have digits left of the decimal point (this may include digits
+   * which have been moved left because of percent or permille formatting),
+   * or because the minimum number of printable digits is greater than 1.
    */
-  bool _hasPrintableIntegerPart(x) =>
-      x > 0 || minimumIntegerDigits > 0;
+  bool _hasIntegerDigits(String digits) =>
+      digits.isNotEmpty || minimumIntegerDigits > 0;
 
   /** A group of methods that provide support for writing digits and other
    * required characters into [_buffer] easily.
    */
   void _add(String x) { _buffer.write(x);}
   void _addCharCode(int x) { _buffer.writeCharCode(x);}
   void _addZero() { _buffer.write(symbols.ZERO_DIGIT);}
   void _addDigit(int x) { _buffer.writeCharCode(_localeZero + x - _zero);}
 
   /** Print padding up to [numberOfDigits] above what's included in [basic]. */
@@ skipping 656 matching lines @@
   String get peek => nextIndex >= input.length ? null : input[nextIndex];
 
   Iterator<String> get iterator => this;
 
   static String _validate(input) {
     if (input is! String) throw new ArgumentError(input);
     return input;
   }
 
 }