Fixed KT-5396 J2K: properly format "else if" on conversion

#KT-5396 Fixed

j2k/src/org/jetbrains/jet/j2k/ast/Statements.kt

@@ -58,12 +58,14 @@ class IfStatement(
         val elseStatement: Element,
         singleLine: Boolean
 ) : Expression() {
+
     private val br = if (singleLine) " " else "\n"
+    private val brAfterElse = if (singleLine || elseStatement is IfStatement) " " else "\n"
 
     override fun generateCode(builder: CodeBuilder) {
         builder append "if (" append condition append ")" append br append thenStatement
         if (!elseStatement.isEmpty) {
-            builder append br append "else" append br append elseStatement
+            builder append br append "else" append brAfterElse append elseStatement
         }
     }
 }

j2k/tests/test/org/jetbrains/jet/j2k/test/JavaToKotlinConverterTestGenerated.java

@@ -1512,6 +1512,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), "org.jetbrains.jet.generators.tests.TestsPackage", new File("j2k/tests/testData/ast/ifStatement"), Pattern.compile("^(.+)\\.java$"), true);
         }
         
+        @TestMetadata("elseIf.java")
+        public void testElseIf() throws Exception {
+            doTest("j2k/tests/testData/ast/ifStatement/elseIf.java");
+        }
+        
         @TestMetadata("multiLine.java")
         public void testMultiLine() throws Exception {
             doTest("j2k/tests/testData/ast/ifStatement/multiLine.java");

j2k/tests/testData/ast/ifStatement/elseIf.java

@@ -0,0 +1,16 @@
+//method
+void foo() {
+  if (a)
+    System.out.println("a")
+  else if (b)
+    System.out.println("b")
+  else
+    System.out.println("else")
+
+  if (c) {
+    System.out.println("c")
+  }
+  else if (d) {
+    System.out.println("d")
+  }
+}

j2k/tests/testData/ast/ifStatement/elseIf.kt

@@ -0,0 +1,14 @@
+fun foo() {
+    if (a)
+        System.out.println("a")
+    else if (b)
+        System.out.println("b")
+    else
+        System.out.println("else")
+
+    if (c) {
+        System.out.println("c")
+    } else if (d) {
+        System.out.println("d")
+    }
+}