JetDecomposerPattern.getArgumentList() may return null

compiler/frontend/src/org/jetbrains/jet/lang/cfg/JetControlFlowProcessor.java

@@ -124,7 +124,10 @@ public class JetControlFlowProcessor {
             @Override
             public void visitDecomposerPattern(JetDecomposerPattern pattern) {
                 value(pattern.getDecomposerExpression(), inCondition);
-                pattern.getArgumentList().accept(this);
+                JetTuplePattern argumentList = pattern.getArgumentList();
+                if (argumentList != null) {
+                    argumentList.accept(this);
+                }
             }
 
             @Override

compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDecomposerPattern.java

@@ -18,6 +18,7 @@ public class JetDecomposerPattern extends JetPattern {
         return findChildByClass(JetExpression.class);
     }
 
+    @Nullable
     public JetTuplePattern getArgumentList() {
         return (JetTuplePattern) findChildByType(JetNodeTypes.DECOMPOSER_ARGUMENT_LIST);
     }

compiler/frontend/src/org/jetbrains/jet/lang/types/expressions/PatternMatchingTypingVisitor.java

@@ -204,9 +204,11 @@ public class PatternMatchingTypingVisitor extends ExpressionTypingVisitor {
                     ReceiverDescriptor receiver = new TransientReceiver(subjectType);
                     JetType selectorReturnType = facade.getSelectorReturnType(receiver, null, decomposerExpression, context);
 
-                    result.set(checkPatternType(pattern.getArgumentList(), selectorReturnType == null
+                    if (pattern.getArgumentList() != null) {
+                        result.set(checkPatternType(pattern.getArgumentList(), selectorReturnType == null
                                                                            ? ErrorUtils.createErrorType("No type")
                                                                            : selectorReturnType, false, scopeToExtend, context));
+                    }
                 }
             }