From 6b81b307b7350c255553210375b8808104d26a3e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20K=C3=A4berich?= <j.kaeberich@gmx.de>
Date: Mon, 12 May 2025 16:56:38 +0200
Subject: [PATCH] Fix: do not reset variable names for from math traces when
 opening trace edit dialog

---
 Software/PC_Application/LibreVNA-GUI/Traces/trace.cpp    | 9 +++++++++
 .../LibreVNA-GUI/Traces/traceeditdialog.cpp              | 7 ++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/trace.cpp b/Software/PC_Application/LibreVNA-GUI/Traces/trace.cpp
index 99d2d46..40b1761 100644
--- a/Software/PC_Application/LibreVNA-GUI/Traces/trace.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/Traces/trace.cpp
@@ -551,6 +551,10 @@ void Trace::scheduleMathCalculation(unsigned int begin, unsigned int end)
 void Trace::calculateMath()
 {
     lastMathUpdate = QTime::currentTime();
+    if(mathUpdateEnd <= mathUpdateBegin) {
+        // nothing to do
+        return;
+    }
     if(mathUpdateBegin >= data.size() || mathUpdateEnd >= data.size() + 1) {
         qWarning() << "Not calculating math trace, out of limits. Requested from" << mathUpdateBegin << "to" << mathUpdateEnd <<" but data is of size" << data.size();
         return;
@@ -660,6 +664,11 @@ bool Trace::canAddAsMathSource(Trace *t)
 
 bool Trace::addMathSource(Trace *t, QString variableName)
 {
+    if(mathSourceTraces.count(t)) {
+        // this trace is already used as a math source
+        mathSourceTraces[t] = variableName;
+        return true;
+    }
 //    qDebug() << "Adding trace" << t << "as a math source to" << this << "as variable" << variableName;
     if(!canAddAsMathSource(t)) {
         return false;
diff --git a/Software/PC_Application/LibreVNA-GUI/Traces/traceeditdialog.cpp b/Software/PC_Application/LibreVNA-GUI/Traces/traceeditdialog.cpp
index ba4121b..1accf75 100644
--- a/Software/PC_Application/LibreVNA-GUI/Traces/traceeditdialog.cpp
+++ b/Software/PC_Application/LibreVNA-GUI/Traces/traceeditdialog.cpp
@@ -172,6 +172,7 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
             if(t.mathDependsOn(ts, true)) {
                 traceItem->setCheckState(Qt::Checked);
                 variableItem->setFlags(variableItem->flags() | Qt::ItemIsEnabled | Qt::ItemIsEditable);
+                ui->mathTraceTable->blockSignals(false);
             } else {
                 traceItem->setCheckState(Qt::Unchecked);
             }
@@ -181,7 +182,7 @@ TraceEditDialog::TraceEditDialog(Trace &t, QWidget *parent) :
         connect(ui->mathTraceTable, &QTableWidget::itemChanged, [&](QTableWidgetItem *item){
             auto row = ui->mathTraceTable->row(item);
             auto column = ui->mathTraceTable->column(item);
-            qDebug() << "Item changed at row"<<row<<"column"<<column;
+//            qDebug() << "Item changed at row"<<row<<"column"<<column;
             ui->mathTraceTable->blockSignals(true);
             auto trace = t.getModel()->trace(row);
             if(column == 0) {
@@ -408,6 +409,9 @@ bool TraceEditDialog::updateMathFormulaStatus()
 void TraceEditDialog::updateMathFormulaSelectableRows()
 {
     // available trace selections may have changed, disable/enable other rows
+
+    // block signals, otherwise the trace names will be reset
+    ui->mathTraceTable->blockSignals(true);
     for(unsigned int i=0;i<trace.getModel()->getTraces().size();i++) {
         auto traceItem = ui->mathTraceTable->item(i, 0);
         auto flags = traceItem->flags();
@@ -418,6 +422,7 @@ void TraceEditDialog::updateMathFormulaSelectableRows()
             traceItem->setFlags(flags & ~Qt::ItemIsEnabled);
         }
     }
+    ui->mathTraceTable->blockSignals(false);
 }
 
 MathModel::MathModel(Trace &t, QObject *parent)