Java to Kotlin converter: fixed crash in converter + more correct auto insertion of !!

#KT-851 Fixed

j2k/src/org/jetbrains/jet/j2k/Converter.kt

@@ -569,9 +569,9 @@ public class Converter private(val project: Project, val settings: ConverterSett
         val actualType = expression.getType()
         if (actualType == null) return convertedExpression
 
-        if (actualType is PsiPrimitiveType && convertedExpression.isNullable ||
-                expectedType is PsiPrimitiveType && actualType is PsiClassType) {
-            convertedExpression = BangBangExpression(convertedExpression)
+        if (convertedExpression.isNullable &&
+                (actualType is PsiPrimitiveType || actualType is PsiClassType && expectedType is PsiPrimitiveType)) {
+            convertedExpression = BangBangExpression(convertedExpression).assignNoPrototype()
         }
 
         if (canConvertType(actualType, expectedType) && convertedExpression !is LiteralExpression) {

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

@@ -1672,6 +1672,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/issues/kt-837.java");
         }
         
+        @TestMetadata("kt-851.java")
+        public void testKt_851() throws Exception {
+            doTest("j2k/tests/testData/ast/issues/kt-851.java");
+        }
+        
         @TestMetadata("kt-852.java")
         public void testKt_852() throws Exception {
             doTest("j2k/tests/testData/ast/issues/kt-852.java");

j2k/tests/testData/ast/issues/kt-794-mixed.kt

@@ -6,6 +6,6 @@ class Test() {
     }
 
     fun test() {
-        val i = getInteger(10)!!
+        val i = getInteger(10)
     }
 }

j2k/tests/testData/ast/issues/kt-851.java

@@ -0,0 +1,9 @@
+//file
+class Test {
+    void putInt(int i) {}
+
+    void test() {
+        Byte b = 10;
+        putInt(b);
+    }
+}

j2k/tests/testData/ast/issues/kt-851.kt

@@ -0,0 +1,9 @@
+class Test() {
+    fun putInt(i: Int) {
+    }
+
+    fun test() {
+        val b = 10
+        putInt(b.toInt())
+    }
+}

j2k/tests/testData/ast/kotlinApiAccess/GlobalGenericFunction.kt

@@ -2,6 +2,6 @@ import kotlinApi.*
 
 class C() {
     fun foo() {
-        val v = globalGenericFunction<Int>(1)!!
+        val v = globalGenericFunction<Int>(1)
     }
 }

j2k/tests/testData/ast/localVariable/autoBangBang.kt

@@ -1,4 +1,4 @@
 fun foo(i: Int) {
-    var i1 = i!!
+    var i1 = i
     i1++
 }