decompiler: fixed incorrect method references from single letter classes

src/org/jetbrains/java/decompiler/main/ClassWriter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2015 JetBrains s.r.o.
+ * Copyright 2000-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -98,7 +98,7 @@ public class ClassWriter {
         }
         else {
           // reference to a static method
-          buffer.append(ExprProcessor.getCastTypeName(new VarType(node.lambdaInformation.content_class_name, false)));
+          buffer.append(ExprProcessor.getCastTypeName(new VarType(node.lambdaInformation.content_class_name, true)));
         }
 
         buffer.append("::");

test/org/jetbrains/java/decompiler/SingleClassesTest.java

@@ -80,6 +80,7 @@ public class SingleClassesTest {
   @Test public void testStringConcat() { doTest("pkg/TestStringConcat"); }
   @Test public void testJava9StringConcat() { doTest("java9/TestJava9StringConcat"); }
   @Test public void testMethodReferenceSameName() { doTest("pkg/TestMethodReferenceSameName"); }
+  @Test public void testMethodReferenceLetterClass() { doTest("pkg/TestMethodReferenceLetterClass"); }
 
   protected void doTest(String testFile, String... companionFiles) {
     ConsoleDecompiler decompiler = fixture.getDecompiler();

testData/results/TestMethodReferenceLetterClass.dec

@@ -0,0 +1,18 @@
+import java.util.function.Consumer;
+
+public class TestMethodReferenceLetterClass {
+   void boo() {
+      Consumer var1 = R::foo;// 21
+   }// 22
+}
+
+class 'TestMethodReferenceLetterClass' {
+   method 'boo ()V' {
+      5      4
+      6      5
+   }
+}
+
+Lines mapping:
+21 <-> 5
+22 <-> 6

testData/src/pkg/TestMethodReferenceLetterClass.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2000-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.util.function.Consumer;
+
+public class TestMethodReferenceLetterClass {
+  void boo() {
+    Consumer<R> foo = R::foo;
+  }
+}
+
+class R {
+  void foo() {}
+}