correct errors not being highlighted on start up

the problem occurred because the cursor was not valid, which caused the
extra selections to contain invalid cursor preventing the errors from
being highlighted

a new cursor valid flag member added to the edit box class, which is
initialized to false and only set to true when a cursor move signal is
received, at which time the extra selection list is updated from the
saved error list

a new error list member added to edit box where the received errors list
from the program model is saved (will be needed later anyway to access
the error messages) and the extra selection list will only be updated if
the cursor is valid

editbox.cpp

@@ -37,7 +37,8 @@ EditBox::EditBox(QWidget *parent) :
 	QPlainTextEdit(parent),
 	m_modifiedLine(-1),
 	m_modifiedLineIsNew(false),
-	m_lineCount(0)
+	m_lineCount(0),
+	m_cursorValid(false)
 {
 	// set the edit box to a fixed width font
 	QFont font = this->font();
@@ -350,6 +351,11 @@ void EditBox::documentChanged(int position, int charsRemoved, int charsAdded)
 
 void EditBox::cursorMoved(void)
 {
+	if (!m_cursorValid)
+	{
+		m_cursorValid = true;
+		updateErrors(m_errors);
+	}
 	if (m_modifiedLine >= 0 && m_modifiedLine != textCursor().blockNumber())
 	{
 		// there is a modified line and cursor moved from that line
@@ -385,6 +391,12 @@ void EditBox::captureModifiedLine(int offset)
 // function to update errors when program error list changes
 void EditBox::updateErrors(const ErrorList &errors)
 {
+	m_errors = errors;
+	if (!m_cursorValid)
+	{
+		return;  // wait until cursor is valid
+	}
+
 	int inserted = errors.size() - m_extraSelections.size();
 	int removed;
 	if (inserted > 0)

editbox.h

@@ -29,9 +29,9 @@
 #include <QPlainTextEdit>
 #include <QTextBlock>
 
+#include "errorlist.h"
+
 class QEvent;
-class ErrorItem;
-class ErrorList;
 
 
 class EditBox : public QPlainTextEdit
@@ -80,6 +80,8 @@ private slots:
 	int m_lineCount;				// total document line count
 	QList<QTextEdit::ExtraSelection>
 		m_extraSelections;			// error highlight extra selections
+	bool m_cursorValid;				// flag for when text cursor is valid
+	ErrorList m_errors;				// list of errors from the program model
 };