OC-3672 Comment line doesn't move cursor on the next line if it is located next to a argument placeholder

platform/lang-impl/src/com/intellij/codeInsight/generation/CommentByLineCommentHandler.java

@@ -97,6 +97,12 @@ public class CommentByLineCommentHandler implements CodeInsightActionHandler {
     myStartOffset = selectionModel.getSelectionStart();
     myEndOffset = selectionModel.getSelectionEnd();
 
+    FoldRegion fold = myEditor.getFoldingModel().getCollapsedRegionAtOffset(myStartOffset);
+    if (fold != null && fold.shouldNeverExpand() && fold.getStartOffset() == myStartOffset && fold.getEndOffset() == myEndOffset) {
+      // Foldings that never expand are automatically selected, so the fact it is selected must not interfer with commenter's logic
+      hasSelection = false;
+    }
+
     if (myDocument.getTextLength() == 0) return;
 
     while (true) {
@@ -648,4 +654,4 @@ public class CommentByLineCommentHandler implements CodeInsightActionHandler {
       }
     }
   }
-}
+}

platform/platform-impl/src/com/intellij/openapi/editor/impl/CaretModelImpl.java

@@ -196,6 +196,7 @@ public class CaretModelImpl implements CaretModel, PrioritizedDocumentListener,
       for (CaretListener listener : myCaretListeners) {
         listener.caretPositionChanged(event);
       }
+      EditorActionUtil.selectNonexpandableFold(myEditor);
     }
   }
 
@@ -237,6 +238,7 @@ public class CaretModelImpl implements CaretModel, PrioritizedDocumentListener,
       for (CaretListener listener : myCaretListeners) {
         listener.caretPositionChanged(event);
       }
+      EditorActionUtil.selectNonexpandableFold(myEditor);
     }
   }
 
@@ -593,6 +595,7 @@ public class CaretModelImpl implements CaretModel, PrioritizedDocumentListener,
           listener.caretPositionChanged(event);
         }
       }
+      EditorActionUtil.selectNonexpandableFold(myEditor);
     }
     return null;
   }