Disable new api for o commands

src/main/java/com/maddyhome/idea/vim/action/change/insert/InsertNewLineBelowAction.kt

@@ -26,7 +26,6 @@ import com.maddyhome.idea.vim.command.CommandFlags
 import com.maddyhome.idea.vim.command.OperatorArguments
 import com.maddyhome.idea.vim.handler.ChangeEditorActionHandler
 import com.maddyhome.idea.vim.helper.enumSetOf
-import com.maddyhome.idea.vim.helper.experimentalApi
 import com.maddyhome.idea.vim.newapi.insertLineAround
 import java.util.*
 
@@ -42,7 +41,9 @@ class InsertNewLineBelowAction : ChangeEditorActionHandler.SingleExecution() {
     operatorArguments: OperatorArguments,
   ): Boolean {
     if (editor.isOneLineMode) return false
-    if (experimentalApi()) {
+//    if (experimentalApi()) {
+    @Suppress("ConstantConditionIf")
+    if (false) {
       insertLineAround(editor, context, 1)
     } else {
       VimPlugin.getChange().insertNewLineBelow(editor, context)
@@ -63,7 +64,9 @@ class InsertNewLineAboveAction : ChangeEditorActionHandler.SingleExecution() {
     operatorArguments: OperatorArguments,
   ): Boolean {
     if (editor.isOneLineMode) return false
-    if (experimentalApi()) {
+//    if (experimentalApi()) {
+    @Suppress("ConstantConditionIf")
+    if (false) {
       insertLineAround(editor, context, 0)
     } else {
       VimPlugin.getChange().insertNewLineAbove(editor, context)

src/main/java/com/maddyhome/idea/vim/group/ChangeGroup.java

@@ -171,12 +171,15 @@ public class ChangeGroup {
     if (editor.isOneLineMode()) return;
 
     // See also EditorStartNewLineBefore. That will move the caret to line start, call EditorEnter to create a new line,
-    // and then move up and call EditorLineEnd. We get better indent positioning by going to the line end of the
-    // previous line and hitting enter, especially with plain text files.
+    //   and then move up and call EditorLineEnd. We get better indent positioning by going to the line end of the
+    //   previous line and hitting enter, especially with plain text files.
+    // However, we'll use EditorStartNewLineBefore in PyCharm notebooks where the last character of the previous line
+    //   may be locked with a guard
 
     // Note that we're deliberately bypassing MotionGroup.moveCaret to avoid side effects, most notably unncessary
     // scrolling
     Set<Caret> firstLiners = new HashSet<>();
+    Set<Pair<Caret, Integer>> moves = new HashSet<>();
     for (Caret caret : editor.getCaretModel().getAllCarets()) {
       final int offset;
       if (caret.getVisualPosition().line == 0) {
@@ -187,17 +190,29 @@ public class ChangeGroup {
       else {
         offset = VimPlugin.getMotion().moveCaretToLineEnd(editor, caret.getLogicalPosition().line - 1, true);
       }
-      caret.moveToOffset(offset);
+      moves.add(new Pair<>(caret, offset));
     }
 
-    initInsert(editor, context, CommandState.Mode.INSERT);
-    runEnterAction(editor, context);
-
-    for (Caret caret : editor.getCaretModel().getAllCarets()) {
-      if (firstLiners.contains(caret)) {
-        final int offset = VimPlugin.getMotion().moveCaretToLineEnd(editor, 0, true);
-        MotionGroup.moveCaret(editor, caret, offset);
+    // Check if the "last character on previous line" has a guard
+    // This is actively used in pycharm notebooks https://youtrack.jetbrains.com/issue/VIM-2495
+    boolean hasGuards = moves.stream().anyMatch(it -> editor.getDocument().getOffsetGuard(it.getSecond()) != null);
+    if (!hasGuards) {
+      for (Pair<Caret, Integer> move : moves) {
+        move.getFirst().moveToOffset(move.getSecond());
       }
+
+      initInsert(editor, context, CommandState.Mode.INSERT);
+      runEnterAction(editor, context);
+
+      for (Caret caret : editor.getCaretModel().getAllCarets()) {
+        if (firstLiners.contains(caret)) {
+          final int offset = VimPlugin.getMotion().moveCaretToLineEnd(editor, 0, true);
+          MotionGroup.moveCaret(editor, caret, offset);
+        }
+      }
+    } else {
+      initInsert(editor, context, CommandState.Mode.INSERT);
+      runEnterAboveAction(editor, context);
     }
 
     MotionGroup.scrollCaretIntoView(editor);
@@ -278,6 +293,19 @@ public class ChangeGroup {
     }
   }
 
+  private void runEnterAboveAction(Editor editor, @NotNull DataContext context) {
+    CommandState state = CommandState.getInstance(editor);
+    if (!state.isDotRepeatInProgress()) {
+      // While repeating the enter action has been already executed because `initInsert` repeats the input
+      final ActionManager actionManager = ActionManager.getInstance();
+      final AnAction action = actionManager.getAction("EditorStartNewLineBefore");
+      if (action != null) {
+        strokes.add(action);
+        KeyHandler.executeAction(action, context);
+      }
+    }
+  }
+
   /**
    * Begin insert at the location of the previous insert
    *

src/main/java/com/maddyhome/idea/vim/newapi/ChangeGroup.kt

@@ -135,6 +135,8 @@ fun deleteRange(
 }
 
 /**
+ * XXX: This implementation is incorrect!
+ *
  * Known issues of this code:
  * - Indent is incorrect when `o` for kotlin code like
  *   ```