diff --git a/RedPandaIDE/qsynedit/SynEdit.cpp b/RedPandaIDE/qsynedit/SynEdit.cpp
index 50c9cb08..d17406b0 100644
--- a/RedPandaIDE/qsynedit/SynEdit.cpp
+++ b/RedPandaIDE/qsynedit/SynEdit.cpp
@@ -3425,7 +3425,7 @@ QString SynEdit::expandAtWideGlyphs(const QString &S)
 
 void SynEdit::updateModifiedStatus()
 {
-    setModified(!mUndoList->initialState());
+    setModified(!mUndoList->isEmpty());
 }
 
 int SynEdit::scanFrom(int Index, int canStopIndex)
@@ -6689,8 +6689,6 @@ void SynEdit::onUndoAdded()
     if (! mUndoList->insideRedo() &&
             mUndoList->peekItem() && (mUndoList->peekItem()->changeReason()!=SynChangeReason::GroupBreak))
         mRedoList->clear();
-    if (mUndoList->blockCount() == 0 )
-        onChanged();
 }
 
 SynSelectionMode SynEdit::activeSelectionMode() const
@@ -6901,9 +6899,6 @@ void SynEdit::setTopLine(int Value)
 void SynEdit::onRedoAdded()
 {
     updateModifiedStatus();
-
-    if (mRedoList->blockCount() == 0 )
-        onChanged();
 }
 
 void SynEdit::onGutterChanged()
diff --git a/RedPandaIDE/qsynedit/TextBuffer.cpp b/RedPandaIDE/qsynedit/TextBuffer.cpp
index 20a71455..82d70864 100644
--- a/RedPandaIDE/qsynedit/TextBuffer.cpp
+++ b/RedPandaIDE/qsynedit/TextBuffer.cpp
@@ -840,9 +840,8 @@ SynEditUndoList::SynEditUndoList():QObject()
     mInsideRedo = false;
 
     mBlockChangeNumber=0;
-    mBlockCount=0;
+    mBlockLockCount=0;
     mFullUndoImposible=false;
-    mLockCount = 0;
     mInitialChangeNumber = 0;
 }
 
@@ -850,24 +849,19 @@ void SynEditUndoList::addChange(SynChangeReason AReason, const BufferCoord &ASta
                                 const BufferCoord &AEnd, const QStringList& ChangeText,
                                 SynSelectionMode SelMode)
 {
-    if (mLockCount != 0)
-        return;
     int changeNumber;
-    if (mBlockChangeNumber != 0) {
+    if (inBlock()) {
         changeNumber = mBlockChangeNumber;
     } else {
-        changeNumber = mNextChangeNumber;
-        if (mBlockCount == 0) {
-            mNextChangeNumber++;
-            if (mNextChangeNumber == 0) {
-                mNextChangeNumber++;
-            }
-        }
+        changeNumber = getNextChangeNumber();
     }
     PSynEditUndoItem  NewItem = std::make_shared<SynEditUndoItem>(AReason,
                                                                   SelMode,AStart,AEnd,ChangeText,
                                                                   changeNumber);
     pushItem(NewItem);
+    if (mBlockLockCount == 0) {
+        emit addedUndo();
+    }
 }
 
 void SynEditUndoList::addGroupBreak()
@@ -882,8 +876,8 @@ void SynEditUndoList::addGroupBreak()
 
 void SynEditUndoList::beginBlock()
 {
-    mBlockCount++;
-    mBlockChangeNumber = mNextChangeNumber;
+    mBlockLockCount++;
+    mBlockChangeNumber = getNextChangeNumber();
 }
 
 void SynEditUndoList::clear()
@@ -902,20 +896,27 @@ void SynEditUndoList::deleteItem(int index)
 
 void SynEditUndoList::endBlock()
 {
-    if (mBlockCount > 0) {
-        mBlockCount--;
-        if (mBlockCount == 0)  {
+    if (mBlockLockCount > 0) {
+        mBlockLockCount--;
+        if (mBlockLockCount == 0)  {
             int iBlockID = mBlockChangeNumber;
             mBlockChangeNumber = 0;
-            mNextChangeNumber++;
-            if (mNextChangeNumber == 0)
-                mNextChangeNumber++;
             if (mItems.count() > 0 && peekItem()->changeNumber() == iBlockID)
                 emit addedUndo();
         }
     }
 }
 
+bool SynEditUndoList::inBlock()
+{
+    return mBlockLockCount>0;
+}
+
+unsigned int SynEditUndoList::getNextChangeNumber()
+{
+    return mNextChangeNumber++;
+}
+
 SynChangeReason SynEditUndoList::lastChangeReason()
 {
     if (mItems.count() == 0)
@@ -929,11 +930,6 @@ bool SynEditUndoList::isEmpty()
     return mItems.count()==0;
 }
 
-void SynEditUndoList::lock()
-{
-    mLockCount++;
-}
-
 PSynEditUndoItem SynEditUndoList::peekItem()
 {
     if (mItems.count() == 0)
@@ -959,14 +955,6 @@ void SynEditUndoList::pushItem(PSynEditUndoItem Item)
         return;
     mItems.append(Item);
     ensureMaxEntries();
-    if (Item->changeReason()!= SynChangeReason::GroupBreak)
-        emit addedUndo();
-}
-
-void SynEditUndoList::unlock()
-{
-    if (mLockCount > 0)
-        mLockCount--;
 }
 
 bool SynEditUndoList::canUndo()
@@ -992,15 +980,6 @@ void SynEditUndoList::setMaxUndoActions(int maxUndoActions)
     }
 }
 
-bool SynEditUndoList::initialState()
-{
-    if (itemCount() == 0) {
-        return mInitialChangeNumber == 0;
-    } else {
-        return peekItem()->changeNumber() == mInitialChangeNumber;
-    }
-}
-
 PSynEditUndoItem SynEditUndoList::item(int index)
 {
     if (index <0 || index>=mItems.count()) {
@@ -1009,22 +988,6 @@ PSynEditUndoItem SynEditUndoList::item(int index)
     return mItems[index];
 }
 
-void SynEditUndoList::setInitialState(const bool Value)
-{
-    if (Value) {
-        if (itemCount() == 0)
-            mInitialChangeNumber = 0;
-        else
-            mInitialChangeNumber = peekItem()->changeNumber();
-    } else if (itemCount() == 0) {
-        if (mInitialChangeNumber == 0) {
-            mInitialChangeNumber = -1;
-        }
-    } else if (peekItem()->changeNumber() == mInitialChangeNumber) {
-        mInitialChangeNumber = -1;
-    }
-}
-
 void SynEditUndoList::setItem(int index, PSynEditUndoItem Value)
 {
     if (index <0 || index>=mItems.count()) {
@@ -1043,11 +1006,6 @@ void SynEditUndoList::setBlockChangeNumber(int blockChangeNumber)
     mBlockChangeNumber = blockChangeNumber;
 }
 
-int SynEditUndoList::blockCount() const
-{
-    return mBlockCount;
-}
-
 bool SynEditUndoList::insideRedo() const
 {
     return mInsideRedo;
diff --git a/RedPandaIDE/qsynedit/TextBuffer.h b/RedPandaIDE/qsynedit/TextBuffer.h
index 79bf9144..cf06d8e4 100644
--- a/RedPandaIDE/qsynedit/TextBuffer.h
+++ b/RedPandaIDE/qsynedit/TextBuffer.h
@@ -172,6 +172,7 @@ enum class SynChangeReason {
     MoveSelectionDown,
     Nothing // undo list empty
   };
+
 class SynEditUndoItem {
 private:
     SynChangeReason mChangeReason;
@@ -179,7 +180,7 @@ private:
     BufferCoord mChangeStartPos;
     BufferCoord mChangeEndPos;
     QStringList mChangeText;
-    int mChangeNumber;
+    size_t mChangeNumber;
 public:
     SynEditUndoItem(SynChangeReason reason,
         SynSelectionMode selMode,
@@ -207,32 +208,29 @@ public:
 
     void addGroupBreak();
     void beginBlock();
+    void endBlock();
+
     void clear();
     void deleteItem(int index);
-    void endBlock();
     SynChangeReason lastChangeReason();
     bool isEmpty();
-    void lock();
     PSynEditUndoItem peekItem();
     PSynEditUndoItem popItem();
     void pushItem(PSynEditUndoItem Item);
-    void unlock();
+
 
     bool canUndo();
     int itemCount();
 
     int maxUndoActions() const;
     void setMaxUndoActions(int maxUndoActions);
-    bool initialState();
+
     PSynEditUndoItem item(int index);
-    void setInitialState(const bool Value);
     void setItem(int index, PSynEditUndoItem Value);
 
     int blockChangeNumber() const;
     void setBlockChangeNumber(int blockChangeNumber);
 
-    int blockCount() const;
-
     bool insideRedo() const;
     void setInsideRedo(bool insideRedo);
 
@@ -242,15 +240,15 @@ signals:
     void addedUndo();
 protected:
     void ensureMaxEntries();
+    bool inBlock();
+    unsigned int getNextChangeNumber();
 protected:
-    int mBlockChangeNumber;
-    int mBlockCount;
+    size_t mBlockChangeNumber;
+    int mBlockLockCount;
     bool mFullUndoImposible;
     QVector<PSynEditUndoItem> mItems;
-    int mLockCount;
     int mMaxUndoActions;
-    int mNextChangeNumber;
-    int mInitialChangeNumber;
+    size_t mNextChangeNumber;
     bool mInsideRedo;
 };