painless: Fix issue with dup and cast

modules/lang-painless/src/main/java/org/elasticsearch/painless/node/EChain.java

@@ -234,15 +234,16 @@ public final class EChain extends AExpression {
             final ADefLink lastDef = (ADefLink) last;
             expression.analyze(settings, definition, variables);
             lastDef.storeValueType = expression.expected = expression.actual;
+            actual = read ? lastDef.storeValueType : definition.voidType;
         } else {
             // otherwise we adapt the type of the expression to the store type
             expression.expected = last.after;
             expression.analyze(settings, definition, variables);
+            actual = read ? last.after : definition.voidType;
         }
         expression = expression.cast(settings, definition, variables);
 
         statement = true;
-        actual = read ? last.after : definition.voidType;
     }
 
     private void analyzeRead() {

modules/lang-painless/src/test/java/org/elasticsearch/painless/ArrayTests.java

@@ -62,6 +62,14 @@ public class ArrayTests extends ScriptTestCase {
         assertEquals(6, exec("def x = new int[5]; x[0] = 5; x[0]++; return x[0];"));
     }
     
+    public void testJacksCrazyExpression1() {
+        assertEquals(1, exec("int x; def[] y = new def[1]; x = y[0] = 1; return x;"));
+    }
+    
+    public void testJacksCrazyExpression2() {
+        assertEquals(1, exec("int x; def y = new def[1]; x = y[0] = 1; return x;"));
+    }
+    
     public void testForLoop() {
         assertEquals(999*1000/2, exec("def a = new int[1000]; for (int x = 0; x < a.length; x++) { a[x] = x; } "+
             "int total = 0; for (int x = 0; x < a.length; x++) { total += a[x]; } return total;"));