invert if: fix psi replacement (IDEA-174966)

java/java-impl/src/com/intellij/codeInsight/intention/impl/InvertIfConditionAction.java

@@ -320,11 +320,12 @@ public class InvertIfConditionAction extends PsiElementBaseIntentionAction {
     final Project project = statement.getProject();
     final PsiElementFactory factory = JavaPsiFacade.getInstance(project).getElementFactory();
     final CodeStyleManager codeStyle = CodeStyleManager.getInstance(project);
-    PsiCodeBlock codeBlock = factory.createCodeBlockFromText("{}", statement);
-    codeBlock = (PsiCodeBlock)codeStyle.reformat(codeBlock);
-    codeBlock.add(statement);
-    codeBlock = (PsiCodeBlock)statement.replace(codeBlock);
-    return codeBlock.getStatements()[0];
+    PsiIfStatement ifStatement = (PsiIfStatement)factory.createStatementFromText("if (true) {}", statement);
+    ifStatement = (PsiIfStatement)codeStyle.reformat(ifStatement);
+    PsiStatement thenBranch = ifStatement.getThenBranch();
+    ((PsiBlockStatement)thenBranch).getCodeBlock().add(statement);
+    PsiCodeBlock stmt = ((PsiBlockStatement)statement.replace(thenBranch)).getCodeBlock();
+    return stmt.getStatements()[0];
   }
 
   private static PsiIfStatement addAfterWithinCodeBlock(@NotNull PsiIfStatement ifStatement, @NotNull PsiStatement branch) {

java/java-tests/testData/codeInsight/invertIfCondition/afterNestedIf4.java

@@ -1,8 +1,7 @@
 // "Invert 'if' condition" "true"
 class Main {
     boolean method(boolean a, boolean b) {
-        for (int i = 1; i < 10; i++)
-        {
+        for (int i = 1; i < 10; i++) {
             if (b) {
                 continue;
             }

java/java-tests/testData/codeInsight/invertIfCondition/afterNestedIf5.java

@@ -0,0 +1,14 @@
+// "Invert 'if' condition" "true"
+class Main {
+    Object foo(boolean b1, boolean b2) {
+        if (b1) {
+            return null;
+        } else {
+            if (b2) {
+                return null;
+            }
+            return "a";
+        }
+
+    }
+}

java/java-tests/testData/codeInsight/invertIfCondition/beforeNestedIf5.java

@@ -0,0 +1,12 @@
+// "Invert 'if' condition" "true"
+class Main {
+    Object foo(boolean b1, boolean b2) {
+        if (b1) {
+            return null;
+        } else if (!b<caret>2) {
+            return "a";
+        }
+        
+        return null;
+    }
+}