remove some unnecessary Boolean checks

- checks for true/false and nullptr

src/Gui/CommandView.cpp

@@ -3225,7 +3225,7 @@ bool StdCmdTextureMapping::isActive()
 {
     Gui::MDIView* view = getMainWindow()->activeWindow();
     return view && view->isDerivedFrom(Gui::View3DInventor::getClassTypeId())
-                && (Gui::Control().activeDialog() == nullptr);
+                && (!(Gui::Control().activeDialog()));
 }
 
 DEF_STD_CMD(StdCmdDemoMode)

src/Gui/QuantitySpinBox.cpp

@@ -184,10 +184,10 @@ public:
                 noUnit = false;
             }
 
-            if (noUnit == true &&
-                    (num == plus ||                          // 1+  -> 1mm+
-                     num == minus ||                         // 1-  -> 1mm-
-                    (pos == length - 1 && (pos += 1)))) {    // 1EOL-> 1mmEOL
+            if (noUnit
+                && (num == plus ||                       // 1+  -> 1mm+
+                    num == minus ||                      // 1-  -> 1mm-
+                    (pos == length - 1 && (pos += 1)))) {// 1EOL-> 1mmEOL
                 copy.insert(pos, unitStr);
                 pos += shift = unitStr.length();
                 length += shift;

src/Gui/propertyeditor/PropertyModel.cpp

@@ -245,7 +245,7 @@ static PropertyItem *createPropertyItem(App::Property *prop)
 PropertyModel::GroupInfo &PropertyModel::getGroupInfo(App::Property *prop)
 {
     const char* group = prop->getGroup();
-    bool isEmpty = (group == nullptr || group[0] == '\0');
+    bool isEmpty = (!group || group[0] == '\0');
     QString groupName = QString::fromLatin1(
             isEmpty ? QT_TRANSLATE_NOOP("App::Property", "Base") : group);
 

src/Mod/Drawing/App/FeatureViewSpreadsheet.cpp

@@ -169,7 +169,7 @@ App::DocumentObjectExecReturn *FeatureViewSpreadsheet::execute(void)
             // get the text
             App::Property* prop = sheet->getPropertyByName(address.toString().c_str());
             std::stringstream field;
-            if (prop != nullptr) {
+            if (prop) {
                 if (prop->isDerivedFrom((App::PropertyQuantity::getClassTypeId())))
                     field << static_cast<App::PropertyQuantity*>(prop)->getValue();
                 else if (prop->isDerivedFrom((App::PropertyFloat::getClassTypeId())))

src/Mod/Part/Gui/TaskCheckGeometry.cpp

@@ -172,7 +172,6 @@ QVector<QString> buildBOPCheckResultVector()
   return results;
 }
 
-
 QString getBOPCheckString(const BOPAlgo_CheckStatus &status)
 {
   static QVector<QString> strings = buildBOPCheckResultVector();
@@ -182,7 +181,6 @@ QString getBOPCheckString(const BOPAlgo_CheckStatus &status)
   return strings.at(index);
 }
 
-
 ResultEntry::ResultEntry()
 {
     viewProviderRoot = nullptr;
@@ -204,9 +202,9 @@ ResultEntry::~ResultEntry()
 
 void ResultEntry::buildEntryName()
 {
-  ResultEntry *parentEntry = this;
-    while (parentEntry->parent != nullptr) {
-        ResultEntry *temp = parentEntry->parent;
+    ResultEntry* parentEntry = this;
+    while (parentEntry->parent) {
+        ResultEntry* temp = parentEntry->parent;
         if (!temp->parent)
             break;
         parentEntry = parentEntry->parent;

src/Mod/Sketcher/Gui/TaskSketcherConstraints.cpp

@@ -967,7 +967,7 @@ void TaskSketcherConstraints::on_showHideButton_clicked(bool val)
     bool allSelected = true;
     for (int i = 0; i < ui->listWidgetConstraints->count(); ++i){
         QListWidgetItem* it = ui->listWidgetConstraints->item(i);
-        if (it->isHidden() == false && it->checkState() == Qt::Unchecked) {
+        if (!(it->isHidden()) && it->checkState() == Qt::Unchecked) {
             allSelected = false;
             break;
         }