Bug in FormulaDelegate : string copy was made in a wrong way

src/view/grid/FormulaDelegate.cpp

@@ -23,6 +23,7 @@
 #include "FormulaDelegate.hpp"
 #include <ParseExp.hpp>
 #include "../wxUI.hpp"
+#include <cstring>
 #include <iostream>
 
 QWidget * FormulaDelegate::createEditor (QWidget * parent, const QStyleOptionViewItem & option, const QModelIndex & index ) const
@@ -38,17 +39,17 @@ void FormulaDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,
     double res = 0.0;
     QString value = line->text();
     struct ParseExp::parse_opt opt, *r;
-    const char* c;
     char* str, *str2;
     bool ok;
-
+    std::string ss;
+    
     value = value.trimmed();
     if (value.startsWith("="))
     {
 	value = value.replace(",", ".");
-	c = value.toStdString().c_str();
-	str2 = str = new char[strlen(c)];
-	strcpy(str, c+1);
+	ss = value.toStdString();
+	str2 = str = new char[ss.length()];
+	std::strcpy(str, ss.c_str()+1);
 	memset(&opt, 0, sizeof(opt));
 	r = &opt;
 	try {