Fix curves param losing params on copy/paste, don't allow more than 5 points...

Fix curves param losing params on copy/paste, don't allow more than 5 points in curve (effect doesn't support more)
Fixes #588

src/assets/model/assetparametermodel.cpp

@@ -209,14 +209,21 @@ void AssetParameterModel::internalSetParameter(const QString &name, const QStrin
         QStringList vals = paramValue.split(QLatin1Char(';'), QString::SkipEmptyParts);
         int points = vals.size();
         m_asset->set("3", points / 10.);
+        m_params[QStringLiteral("3")].value = points / 10.;
         // for the curve, inpoints are numbered: 6, 8, 10, 12, 14
         // outpoints, 7, 9, 11, 13,15 so we need to deduce these enums
         for (int i = 0; i < points; i++) {
             const QString &pointVal = vals.at(i);
             int idx = 2 * i + 6;
-            m_asset->set(QString::number(idx).toLatin1().constData(), pointVal.section(QLatin1Char('/'), 0, 0).toDouble());
+            QString pName = QString::number(idx);
+            double val = pointVal.section(QLatin1Char('/'), 0, 0).toDouble();
+            m_asset->set(pName.toLatin1().constData(), val);
+            m_params[pName].value = val;
             idx++;
-            m_asset->set(QString::number(idx).toLatin1().constData(), pointVal.section(QLatin1Char('/'), 1, 1).toDouble());
+            pName = QString::number(idx);
+            val = pointVal.section(QLatin1Char('/'), 1, 1).toDouble();
+            m_asset->set(pName.toLatin1().constData(), val);
+            m_params[pName].value = val;
         }
     }
     bool conversionSuccess;

src/assets/view/widgets/curves/cubic/kis_curve_widget.cpp

@@ -60,6 +60,7 @@ KisCurveWidget::KisCurveWidget(QWidget *parent)
     m_pixmapCache = nullptr;
     m_maxPoints = 0;
     m_curve = KisCubicCurve();
+    setMaxPoints(5);
     update();
 }
 
@@ -134,6 +135,7 @@ void KisCurveWidget::mousePressEvent(QMouseEvent *e)
     if (e->button() == Qt::RightButton && closest_point_index > 0 && closest_point_index < m_curve.points().count() - 1) {
         m_currentPointIndex = closest_point_index;
         slotDeleteCurrentPoint();
+        return;
     } else if (e->button() != Qt::LeftButton) {
         return;
     }