diff --git a/PowerEditor/src/Notepad_plus.cpp b/PowerEditor/src/Notepad_plus.cpp
index fbc457313..7ff00e6c2 100644
--- a/PowerEditor/src/Notepad_plus.cpp
+++ b/PowerEditor/src/Notepad_plus.cpp
@@ -1549,6 +1549,11 @@ BOOL Notepad_plus::notify(SCNotification *notification)
 				_isDocModifing = true;
 				::InvalidateRect(_pEditView->getHSelf(), NULL, TRUE);
 			}
+			if (notification->modificationType & SC_MOD_CHANGEFOLD)
+			{
+				_pEditView->foldChanged(notification->line,
+				        notification->foldLevelNow, notification->foldLevelPrev);
+			}
 		}
 		break;
 
@@ -1986,7 +1991,19 @@ BOOL Notepad_plus::notify(SCNotification *notification)
 		_isHotspotDblClicked = true;
 		_pEditView->execute(SCI_SETCHARSDEFAULT);
 		break;
-	} 
+	}
+
+	case SCN_NEEDSHOWN :
+	{
+		int begin = _pEditView->execute(SCI_LINEFROMPOSITION, notification->position);
+		int end = _pEditView->execute(SCI_LINEFROMPOSITION, notification->position + notification->length);
+		int firstLine = begin < end ? begin : end;
+		int lastLine = begin > end ? begin : end;
+		for (int line = firstLine; line <= lastLine; line++) {
+			_pEditView->execute(SCI_ENSUREVISIBLE, line, 0);
+		}
+		break;
+	}
 
 	default :
 		break;
diff --git a/PowerEditor/src/Notepad_plus.h b/PowerEditor/src/Notepad_plus.h
index 4e4a77cf5..83082c61b 100644
--- a/PowerEditor/src/Notepad_plus.h
+++ b/PowerEditor/src/Notepad_plus.h
@@ -660,9 +660,12 @@ private:
 	void checkLangsMenu(int id) const ;
 
     void setLanguage(int id, LangType langType) {
-        _pEditView->setCurrentDocType(langType);
-        setLangStatus(langType);
-		checkLangsMenu(id);
+        if (_pEditView->setCurrentDocType(langType))
+		{
+			_pEditView->foldAll(fold_uncollapse);
+			setLangStatus(langType);
+			checkLangsMenu(id);
+		}
     };
 
     int getToolBarState() const {
diff --git a/PowerEditor/src/ScitillaComponent/ScintillaEditView.cpp b/PowerEditor/src/ScitillaComponent/ScintillaEditView.cpp
index 91e9d960d..20f61aae5 100644
--- a/PowerEditor/src/ScitillaComponent/ScintillaEditView.cpp
+++ b/PowerEditor/src/ScitillaComponent/ScintillaEditView.cpp
@@ -1723,4 +1723,35 @@ void ScintillaEditView::recalcHorizontalScrollbar()
 	int currentLength = execute(SCI_GETSCROLLWIDTH);					//Get current scrollbar size
 	if (currentLength != maxPixel)										//And if it is not the same
 		execute(SCI_SETSCROLLWIDTH, maxPixel);							//update it
-}
\ No newline at end of file
+}
+
+void ScintillaEditView::foldChanged(int line, int levelNow, int levelPrev)
+{
+	if (levelNow & SC_FOLDLEVELHEADERFLAG)
+	{
+		if (!(levelPrev & SC_FOLDLEVELHEADERFLAG))
+		{
+			// Adding a fold point.
+			execute(SCI_SETFOLDEXPANDED, line, 1);
+			expand(line, true, false, 0, levelPrev);
+		}
+	}
+	else if (levelPrev & SC_FOLDLEVELHEADERFLAG)
+	{
+		if (!execute(SCI_GETFOLDEXPANDED, line))
+		{
+			// Removing the fold from one that has been contracted so should expand
+			// otherwise lines are left invisible with no way to make them visible
+			execute(SCI_SETFOLDEXPANDED, line, 1);
+			expand(line, true, false, 0, levelPrev);
+		}
+	}
+	else if (!(levelNow & SC_FOLDLEVELWHITEFLAG) &&
+	        ((levelPrev & SC_FOLDLEVELNUMBERMASK) > (levelNow & SC_FOLDLEVELNUMBERMASK)))
+	{
+		// See if should still be hidden
+		int parentLine = execute(SCI_GETFOLDPARENT, line);
+		if ((parentLine < 0) || (execute(SCI_GETFOLDEXPANDED, parentLine) && execute(SCI_GETLINEVISIBLE, parentLine)))
+			execute(SCI_SHOWLINES, line, line);
+	}
+}
diff --git a/PowerEditor/src/ScitillaComponent/ScintillaEditView.h b/PowerEditor/src/ScitillaComponent/ScintillaEditView.h
index 65c52052b..43b08b8c4 100644
--- a/PowerEditor/src/ScitillaComponent/ScintillaEditView.h
+++ b/PowerEditor/src/ScitillaComponent/ScintillaEditView.h
@@ -151,14 +151,15 @@ public:
 	
 	void defineDocType(LangType typeDoc);
 
-    void setCurrentDocType(LangType typeDoc) {
+    bool setCurrentDocType(LangType typeDoc) {
         if ((_buffers[_currentIndex]._lang == typeDoc) && (typeDoc != L_USER))
-            return;
+            return false;
 		if (typeDoc == L_USER)
 			_buffers[_currentIndex]._userLangExt[0] = '\0';
 
         _buffers[_currentIndex]._lang = typeDoc;
         defineDocType(typeDoc);
+		return true;
     };
 
 	void setCurrentDocUserType(const char *userLangName) {
@@ -591,7 +592,9 @@ public:
 	void columnReplace(const ColumnModeInfo & cmi, const char ch);
 	void columnReplace(ColumnModeInfo & cmi, int initial, int incr, unsigned char format);
 
-	void ScintillaEditView::recalcHorizontalScrollbar();
+	void recalcHorizontalScrollbar();
+	void foldChanged(int line, int levelNow, int levelPrev);
+
 protected:
 	static HINSTANCE _hLib;
 	static int _refCount;