add <use_no_of_threads> tag to musredit_startup.xml if it is missing and the preferences are saved.

src/musredit_qt5/musredit/PAdmin.cpp

@@ -949,6 +949,7 @@ int PAdmin::savePrefs(QString pref_fln)
     file.close();
 
     // replace all the prefs
+    bool noOfThreadsFound = false;
     for (int i=0; i<data.size(); i++) {
       if (data[i].contains("<timeout>") && data[i].contains("</timeout>")) {
         data[i] = "    <timeout>" + QString("%1").arg(fTimeout) + "</timeout>";
@@ -996,6 +997,7 @@ int PAdmin::savePrefs(QString pref_fln)
           data[i] = "    <yaml_out>n</yaml_out>";
       }
       if (data[i].contains("<use_no_of_threads>") && data[i].contains("</use_no_of_threads>")) {
+        noOfThreadsFound = true;
         data[i] = "    <use_no_of_threads>" + QString("%1").arg(fNoOfThreadsToBeUsed) + "</use_no_of_threads>";
       }
       if (data[i].contains("<musrview_show_fourier>") && data[i].contains("</musrview_show_fourier>")) {
@@ -1042,6 +1044,28 @@ int PAdmin::savePrefs(QString pref_fln)
       }
     }
 
+    // <use_no_of_threads> missing (older startup file): add it, preferably after <yaml_out>, otherwise at the end of <general>
+    if (!noOfThreadsFound) {
+      QString line = "    <use_no_of_threads>" + QString("%1").arg(fNoOfThreadsToBeUsed) + "</use_no_of_threads>";
+      int idx = -1;
+      for (int i=0; i<data.size(); i++) {
+        if (data[i].contains("</yaml_out>")) {
+          idx = i+1;
+          break;
+        }
+      }
+      if (idx == -1) {
+        for (int i=0; i<data.size(); i++) {
+          if (data[i].contains("</general>")) {
+            idx = i;
+            break;
+          }
+        }
+      }
+      if (idx != -1)
+        data.insert(idx, line);
+    }
+
     // write prefs
     file.setFileName(pref_fln);
     if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {

src/musredit_qt6/musredit/PAdmin.cpp

@@ -1095,6 +1095,7 @@ int PAdmin::savePrefs(QString pref_fln)
     file.close();
 
     // replace all the prefs
+    bool noOfThreadsFound = false;
     for (int i=0; i<data.size(); i++) {
       if (data[i].contains("<timeout>") && data[i].contains("</timeout>")) {
         data[i] = "    <timeout>" + QString("%1").arg(fTimeout) + "</timeout>";
@@ -1142,7 +1143,8 @@ int PAdmin::savePrefs(QString pref_fln)
           data[i] = "    <yaml_out>n</yaml_out>";
       }
       if (data[i].contains("<use_no_of_threads>") && data[i].contains("</use_no_of_threads>")) {
-          data[i] = "    <use_no_of_threads>" + QString("%1").arg(fNoOfThreadsToBeUsed) + "</use_no_of_threads>";
+        noOfThreadsFound = true;
+        data[i] = "    <use_no_of_threads>" + QString("%1").arg(fNoOfThreadsToBeUsed) + "</use_no_of_threads>";
       }
       if (data[i].contains("<musrview_show_fourier>") && data[i].contains("</musrview_show_fourier>")) {
         if (fMusrviewShowFourier)
@@ -1188,6 +1190,28 @@ int PAdmin::savePrefs(QString pref_fln)
       }
     }
 
+    // <use_no_of_threads> missing (older startup file): add it, preferably after <yaml_out>, otherwise at the end of <general>
+    if (!noOfThreadsFound) {
+      QString line = "    <use_no_of_threads>" + QString("%1").arg(fNoOfThreadsToBeUsed) + "</use_no_of_threads>";
+      int idx = -1;
+      for (int i=0; i<data.size(); i++) {
+        if (data[i].contains("</yaml_out>")) {
+          idx = i+1;
+          break;
+        }
+      }
+      if (idx == -1) {
+        for (int i=0; i<data.size(); i++) {
+          if (data[i].contains("</general>")) {
+            idx = i;
+            break;
+          }
+        }
+      }
+      if (idx != -1)
+        data.insert(idx, line);
+    }
+
     // write prefs
     file.setFileName(pref_fln);
     if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {