Fix an issue with configuring the severity of lints.

pkg/analyzer/lib/source/error_processor.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.
 
 library analyzer.source.error_processor;
 
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
@@ skipping 15 matching lines @@
   /// Create an error config for the given error code map.
   /// For example:
   ///     new ErrorConfig({'missing_return' : 'error'});
   /// will create a processor config that turns `missing_return` hints into
   /// errors.
   ErrorConfig(Object codeMap) {
     _processMap(codeMap);
   }
 
   void _process(String code, Object action) {
+    code = toUpperCase(code);
     action = toLowerCase(action);
-    code = toUpperCase(code);
     if (AnalyzerOptions.ignoreSynonyms.contains(action)) {
       processors.add(new ErrorProcessor.ignore(code));
     } else {
       ErrorSeverity severity = _toSeverity(action);
       if (severity != null) {
         processors.add(new ErrorProcessor(code, severity));
       }
     }
   }
 
@@ skipping 33 matching lines @@
   /// If [severity] is `null`, matching errors will be filtered.
   ErrorProcessor(this.code, [this.severity]);
 
   /// Create an error processor that ignores the given error by [code].
   factory ErrorProcessor.ignore(String code) => new ErrorProcessor(code);
 
   /// The string that unique describes the processor.
   String get description => '$code -> ${severity?.name}';
 
   /// Check if this processor applies to the given [error].
-  bool appliesTo(AnalysisError error) => code == error.errorCode.name;
+  ///
+  /// Note: [code] is normalized to uppercase; `errorCode.name` for regular
+  /// analysis issues uses uppercase; `errorCode.name` for lints uses lowercase.
+  bool appliesTo(AnalysisError error) =>
+      code == error.errorCode.name ||
+      code == error.errorCode.name.toUpperCase();
 
   /// Return an error processor associated in the [analysisOptions] for the
   /// given [error], or `null` if none is found.
   static ErrorProcessor getProcessor(
       AnalysisOptions analysisOptions, AnalysisError error) {
     if (analysisOptions == null) {
       return null;
     }
 
     // Let the user configure how specific errors are processed.
@@ skipping 29 matching lines @@
     ErrorCode errorCode = error.errorCode;
     if (errorCode is StaticTypeWarningCode) {
       return true;
     }
     if (errorCode is StaticWarningCode) {
       return errorCode.isStrongModeError;
     }
     return false;
   }
 }