8036942: javac generates incorrect exception table for multi-catch statements inside a lambda

Summary: Union type info lost and also union type is not processed by TreeMaker.Type -- address by using existing tree, thus by-passing such issues.
Reviewed-by: vromero, jlahoda

src/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java

@@ -438,13 +438,9 @@ public class LambdaToMethod extends TreeTranslator {
     public void visitVarDef(JCVariableDecl tree) {
         LambdaTranslationContext lambdaContext = (LambdaTranslationContext)context;
         if (context != null && lambdaContext.getSymbolMap(LOCAL_VAR).containsKey(tree.sym)) {
-            JCExpression init = translate(tree.init);
-            int prevPos = make.pos;
-            try {
-                result = make.at(tree).VarDef((VarSymbol)lambdaContext.getSymbolMap(LOCAL_VAR).get(tree.sym), init);
-            } finally {
-                make.at(prevPos);
-            }
+            tree.init = translate(tree.init);
+            tree.sym = (VarSymbol) lambdaContext.getSymbolMap(LOCAL_VAR).get(tree.sym);
+            result = tree;
         } else if (context != null && lambdaContext.getSymbolMap(TYPE_VAR).containsKey(tree.sym)) {
             JCExpression init = translate(tree.init);
             VarSymbol xsym = (VarSymbol)lambdaContext.getSymbolMap(TYPE_VAR).get(tree.sym);
@@ -1895,7 +1891,7 @@ public class LambdaToMethod extends TreeTranslator {
                         };
                         break;
                     case LOCAL_VAR:
-                        ret = new VarSymbol(sym.flags() & FINAL, name, types.erasure(sym.type), translatedSym);
+                        ret = new VarSymbol(sym.flags() & FINAL, name, sym.type, translatedSym);
                         ((VarSymbol) ret).pos = ((VarSymbol) sym).pos;
                         break;
                     case PARAM:

test/tools/javac/lambda/LambdaMultiCatchTest.java

+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug 8036942
+ * @summary javac generates incorrect exception table for multi-catch statements inside a lambda
+ * @run main LambdaMultiCatchTest
+ */
+
+import java.io.IOException;
+import java.util.function.Function;
+
+public class LambdaMultiCatchTest {
+    public static void main(String[] args) {
+        Function<String,String> fi = x -> {
+            String result = "nada";
+            try {
+                switch (x) {
+                    case "IO":  throw new IOException();
+                    case "Illegal": throw new IllegalArgumentException();
+                    case "Run": throw new RuntimeException();
+                }
+            } catch (IOException|IllegalArgumentException ex) {
+               result = "IO/Illegal";
+            } catch (Exception ex) {
+               result = "Any";
+            };
+            return result;
+        };
+        String val = fi.apply("Run");
+        if (!val.equals("Any")) {
+            throw new AssertionError("Fail: Expected 'Any' but got '" + val + "'");
+        }
+    }
+}