Merge pull request #38905 from mantidproject/fix_register_qthelp

Pass DOCS_QTHELP to compiler to control registering MantidHelpWindow

Author: darshdinger

qt/widgets/common/CMakeLists.txt

@@ -636,6 +636,11 @@ if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   list(APPEND TARGET_LIBRARIES "-framework CoreFoundation")
 endif()
 
+# Add option to the compiler to register MantidHelpWindow
+if(DOCS_QTHELP)
+  add_definitions(-DDOCS_QTHELP)
+endif()
+
 # Target Additional components for this module
 find_package(
   Qt5 ${QT_MIN_VERSION}

qt/widgets/common/src/InterfaceManager.cpp

@@ -240,34 +240,40 @@ MantidHelpInterface *InterfaceManager::createHelpWindow() const {
 
 void InterfaceManager::showHelpPage(const QString &url) {
   auto window = createHelpWindow();
-  window->showPage(url);
+  if (window)
+    window->showPage(url);
 }
 
 void InterfaceManager::showAlgorithmHelp(const QString &name, const int version) {
   auto window = createHelpWindow();
-  window->showAlgorithm(name, version);
+  if (window)
+    window->showAlgorithm(name, version);
 }
 
 void InterfaceManager::showConceptHelp(const QString &name) {
   auto window = createHelpWindow();
-  window->showConcept(name);
+  if (window)
+    window->showConcept(name);
 }
 
 void InterfaceManager::showFitFunctionHelp(const QString &name) {
   auto window = createHelpWindow();
-  window->showFitFunction(name);
+  if (window)
+    window->showFitFunction(name);
 }
 
 void InterfaceManager::showCustomInterfaceHelp(const QString &name, const QString &area, const QString &section) {
   auto window = createHelpWindow();
-  window->showCustomInterface(name, area, section);
+  if (window)
+    window->showCustomInterface(name, area, section);
 }
 
 void InterfaceManager::showWebPage(const QString &url) { MantidDesktopServices::openUrl(url); }
 
 void InterfaceManager::closeHelpWindow() {
   if (MantidHelpWindow::helpWindowExists()) {
     auto window = createHelpWindow();
-    window->shutdown();
+    if (window)
+      window->shutdown();
   }
 }