Modified behavior when pressing backspace on a line which has an error marker: the marker is moved to the previous line now.
diff --git a/TextEditor.cpp b/TextEditor.cpp
index 8bb433e..985e802 100644
--- a/TextEditor.cpp
+++ b/TextEditor.cpp
@@ -373,7 +373,7 @@
 	for (auto& i : mErrorMarkers)

 	{

 		ErrorMarkers::value_type e(i.first > aIndex ? i.first - 1 : i.first, i.second);

-		if (e.first == aIndex)

+		if (e.first - 1 == aIndex)

 			continue;

 		etmp.insert(e);

 	}

@@ -1299,7 +1299,6 @@
 	if (mLines.empty())

 		return;

 

-

 	UndoRecord u;

 	u.mBefore = mState;

 

@@ -1329,6 +1328,12 @@
 			auto& prevLine = mLines[mState.mCursorPosition.mLine - 1];

 			auto prevSize = (int)prevLine.size();

 			prevLine.insert(prevLine.end(), line.begin(), line.end());

+

+			ErrorMarkers etmp;

+			for (auto& i : mErrorMarkers)

+				etmp.insert(ErrorMarkers::value_type(i.first - 1 == mState.mCursorPosition.mLine ? i.first - 1 : i.first, i.second));

+			mErrorMarkers = std::move(etmp);

+

 			RemoveLine(mState.mCursorPosition.mLine);

 			--mState.mCursorPosition.mLine;

 			mState.mCursorPosition.mColumn = prevSize;