Fix bug in equalsIgnoreAsciiCase.

lib/src/comparators.dart

 // Copyright (c) 2015, 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.
 
 // Character constants.
 const int _zero         = 0x30;
 const int _upperCaseA   = 0x41;
 const int _upperCaseZ   = 0x5a;
 const int _lowerCaseA   = 0x61;
 const int _lowerCaseZ   = 0x7a;
@@ skipping 16 matching lines @@
 bool equalsIgnoreAsciiCase(String a, String b) {
   if (a.length != b.length) return false;
   for (int i = 0; i < a.length; i++) {
     var aChar = a.codeUnitAt(i);
     var bChar = b.codeUnitAt(i);
     if (aChar == bChar) continue;
     // Quick-check for whether this may be different cases of the same letter.
     if (aChar ^ bChar != _asciiCaseBit) return false;
     // If it's possible, then check if either character is actually an ASCII
     // letter.
-    int aCharUpperCase = aChar | _asciiCaseBit;
-    if (_upperCaseA <= aCharUpperCase && aCharUpperCase <= _upperCaseZ) {
+    int aCharLowerCase = aChar | _asciiCaseBit;
+    if (_lowerCaseA <= aCharLowerCase && aCharLowerCase <= _lowerCaseZ) {
       continue;
     }
     return false;
   }
   return true;
 }
 
 
 /// Hash code for a string which is compatible with [equalsIgnoreAsciiCase].
 ///
@@ skipping 339 matching lines @@
 /// If there is no non-zero digits before, then leading zeros at [index]
 /// are also ignored when comparing numerically. If there is a non-zero digit
 /// before, then zeros at [index] are significant.
 bool _isNonZeroNumberSuffix(String string, int index) {
   while (--index >= 0) {
     int char = string.codeUnitAt(index);
     if (char != _zero) return _isDigit(char);
   }
   return false;
 }