MSForms: Add some extra comments for the new code

Change-Id: I4b70eb2164032623a12f9e703c660eca1d6768ec
Reviewed-on: https://gerrit.libreoffice.org/68965
Tested-by: Jenkins
Reviewed-by: Tamás Zolnai <tamas.zolnai@collabora.com>

sw/qa/extras/globalfilter/globalfilter.cxx

@@ -1225,7 +1225,7 @@ void Test::testDropDownFormField()
                 CPPUNIT_ASSERT_EQUAL_MESSAGE(sFailedMessage.getStr(), sal_Int32(0), vListEntries.getLength());
                 CPPUNIT_ASSERT_EQUAL_MESSAGE(sFailedMessage.getStr(), sal_Int32(-1), nSelection);
             }
-            else
+            else // The second one has list and also a selected item
             {
                 CPPUNIT_ASSERT_EQUAL_MESSAGE(sFailedMessage.getStr(), sal_Int32(4), vListEntries.getLength());
                 CPPUNIT_ASSERT_EQUAL_MESSAGE(sFailedMessage.getStr(), sal_Int32(1), nSelection);

sw/source/core/inc/UndoBookmark.hxx

@@ -98,6 +98,7 @@ private:
     virtual void RedoImpl( ::sw::UndoRedoContext & ) override;
 };
 
+/// Handling undo / redo of checkbox and drop-down form field insertion
 class SwUndoInsNoTextFieldmark : public SwUndo
 {
 private:
@@ -110,6 +111,7 @@ public:
     virtual void RedoImpl( ::sw::UndoRedoContext & ) override;
 };
 
+/// Handling undo / redo of text form field insertion
 class SwUndoInsTextFieldmark : public SwUndo
 {
 private:

sw/source/core/inc/rolbck.hxx

@@ -262,6 +262,8 @@ class SwHistoryBookmark : public SwHistoryHint
         std::shared_ptr< ::sfx2::MetadatableUndo > m_pMetadataUndo;
 };
 
+/// History object containing all information used during undo / redo
+/// of checkbox and drop-down form field insertion.
 class SwHistoryNoTextFieldmark : public SwHistoryHint
 {
     public:
@@ -275,6 +277,8 @@ class SwHistoryNoTextFieldmark : public SwHistoryHint
         const sal_Int32 m_nContent;
 };
 
+/// History object containing all information used during undo / redo
+/// of text form field insertion.
 class SwHistoryTextFieldmark : public SwHistoryHint
 {
     public: