KT-4683 KotlinNullPointerException at remove braces intention

#KT-4683 fixed
 EA-54686 fixed
 EA-54687 fixed

idea/src/org/jetbrains/jet/plugin/intentions/AddBracesIntention.kt

@@ -32,35 +32,32 @@ import org.jetbrains.jet.JetNodeTypes
 import com.intellij.psi.PsiWhiteSpace
 
 public class AddBracesIntention : JetSelfTargetingIntention<JetExpressionImpl>("add.braces", javaClass()) {
-    private var expressionKind: ExpressionKind? = null
+    override fun isApplicableTo(element: JetExpressionImpl): Boolean {
-    private var caretLocation: Int = 1
+        throw IllegalStateException("isApplicableTo(JetExpressionImpl, Editor) should be called instead")
-
-    override fun isAvailable(project: Project, editor: Editor, file: PsiFile): Boolean {
-        caretLocation = editor.getCaretModel().getOffset()
-        return getTarget(editor, file) != null
     }
 
-    override fun isApplicableTo(element: JetExpressionImpl): Boolean {
+    override fun isApplicableTo(element: JetExpressionImpl, editor: Editor): Boolean {
-        expressionKind = element.getExpressionKind(caretLocation)
+        val expressionKind = element.getExpressionKind(editor.getCaretModel().getOffset())
         if (expressionKind == null) return false
 
         val jetBlockElement = element.findBlockInExpression(expressionKind)
         if (jetBlockElement != null) return false
 
-        setText("Add braces to '${expressionKind!!.text}' statement")
+        setText("Add braces to '${expressionKind.text}' statement")
         return true
     }
 
     override fun applyTo(element: JetExpressionImpl, editor: Editor) {
+        val expressionKind = element.getExpressionKind(editor.getCaretModel().getOffset())!!
         val bodyNode = when (expressionKind) {
             ExpressionKind.ELSE -> element.getNode().findChildByType(JetNodeTypes.ELSE)
             ExpressionKind.IF -> element.getNode().findChildByType(JetNodeTypes.THEN)
             else -> element.getNode().findChildByType(JetNodeTypes.BODY)
         }
-        generateCleanOutput(element, bodyNode)
+        generateCleanOutput(element, bodyNode, expressionKind)
     }
 
-    fun generateCleanOutput(element: JetExpressionImpl, bodyNode: ASTNode?) {
+    fun generateCleanOutput(element: JetExpressionImpl, bodyNode: ASTNode?, expressionKind: ExpressionKind) {
         if (element.getNextSibling()?.getText() == ";") {
             element.getNextSibling()!!.delete()
         }

idea/src/org/jetbrains/jet/plugin/intentions/JetSelfTargetingIntention.kt

@@ -30,11 +30,12 @@ public abstract class JetSelfTargetingIntention<T: JetElement>(val key: String,
     }
 
     protected abstract fun isApplicableTo(element: T): Boolean
+    protected open fun isApplicableTo(element: T, editor: Editor): Boolean = isApplicableTo(element)
     protected abstract fun applyTo(element: T, editor: Editor)
 
     protected fun getTarget(editor: Editor, file: PsiFile): T? {
         val offset = editor.getCaretModel().getOffset()
-        return file.findElementAt(offset)?.getParentByTypesAndPredicate(false, elementType) { element -> isApplicableTo(element) }
+        return file.findElementAt(offset)?.getParentByTypesAndPredicate(false, elementType) { element -> isApplicableTo(element, editor) }
     }
 
     public override fun getFamilyName(): String {

idea/src/org/jetbrains/jet/plugin/intentions/RemoveBracesIntention.kt

@@ -30,29 +30,27 @@ import com.intellij.psi.PsiWhiteSpace
 import com.intellij.psi.PsiComment
 
 public class RemoveBracesIntention : JetSelfTargetingIntention<JetExpressionImpl>("remove.braces", javaClass()) {
-    private var expressionKind: ExpressionKind? = null
+    override fun isApplicableTo(element: JetExpressionImpl): Boolean {
-    private var caretLocation: Int = 1
+        throw IllegalStateException("isApplicableTo(JetExpressionImpl, Editor) should be called instead")
-
-    override fun isAvailable(project: Project, editor: Editor, file: PsiFile): Boolean {
-        caretLocation = editor.getCaretModel().getOffset()
-        return getTarget(editor, file) != null
     }
 
-    override fun isApplicableTo(element: JetExpressionImpl): Boolean {
+    override fun isApplicableTo(element: JetExpressionImpl, editor: Editor): Boolean {
-        expressionKind = element.getExpressionKind(caretLocation)
+        val expressionKind = element.getExpressionKind(editor.getCaretModel().getOffset())
         if (expressionKind == null) return false
 
         val jetBlockElement = element.findBlockInExpression(expressionKind)
         if (jetBlockElement == null) return false
 
-        if (jetBlockElement!!.getStatements().size == 1) {
+        if (jetBlockElement.getStatements().size == 1) {
-            setText("Remove braces from '${expressionKind!!.text}' statement")
+            setText("Remove braces from '${expressionKind.text}' statement")
             return true
         }
         return false
     }
 
     override fun applyTo(element: JetExpressionImpl, editor: Editor) {
+        val expressionKind = element.getExpressionKind(editor.getCaretModel().getOffset())!!
+
         val jetBlockElement = element.findBlockInExpression(expressionKind)
         val firstStatement = jetBlockElement!!.getStatements().first()
 
@@ -63,7 +61,6 @@ public class RemoveBracesIntention : JetSelfTargetingIntention<JetExpressionImpl
         if (expressionKind == ExpressionKind.DOWHILE) {
             newElement.getParent()!!.addAfter(JetPsiFactory.createNewLine(element.getProject()), newElement)
         }
-
     }
 
     fun handleComments(element: JetExpressionImpl, blockElement: JetBlockExpression) {