2 files changed, 24 insertions, 7 deletions
diff --git a/ui/qt5/accountpage.cc b/ui/qt5/accountpage.cc
index f4be6ac..bc0eb2f 100644
--- a/ui/qt5/accountpage.cc
+++ b/ui/qt5/accountpage.cc
@@ -11,12 +11,15 @@
  */
 
 #include "accountpage.hh"
+#include "util/user.hh"
+
 #ifdef HAS_INSTALL_ENV
 #   include "commitpage.hh"
 #endif  /* HAS_INSTALL_ENV */
 
 #include <algorithm>
 #include <QLabel>
+#include <QMessageBox>
 #include <QVBoxLayout>
 
 AccountPage::AccountPage(QWidget *parent) : HorizonWizardPage(parent) {
@@ -48,19 +51,35 @@ AccountPage::AccountPage(QWidget *parent) : HorizonWizardPage(parent) {
 }
 
 bool AccountPage::isComplete() const {
-    return std::all_of(accountWidgets.begin(), accountWidgets.end(),
+    return std::all_of(accountWidgets.cbegin(), accountWidgets.cend(),
                        [](UserAccountWidget *widget) {
         if(widget == nullptr) return true;
         return widget->isValid();
     });
 }
 
-#ifdef HAS_INSTALL_ENV
 bool AccountPage::validatePage() {
+#ifdef HAS_INSTALL_ENV
     /* hack to re-initialise page in case the user goes back */
     horizonWizard()->removePage(HorizonWizard::Page_Commit);
     horizonWizard()->setPage(HorizonWizard::Page_Commit, new CommitPage);
+#endif  /* HAS_INSTALL_ENV */
 
-    return true;
+    return std::all_of(accountWidgets.cbegin(), accountWidgets.cend(),
+                       [this](const auto &widget) {
+        auto accountText = widget->accountText();
+        if(accountText.isEmpty()) return true;
+
+        auto username = accountText.toStdString();
+        if(system_names.find(username) != system_names.end() ||
+           system_groups.find(username) != system_groups.end()) {
+            QMessageBox::critical(this, tr("Invalid Username"),
+                                  tr("The username you have chosen (%1) is reserved "
+                                     "by the system.  Choose a different username.")
+                                     .arg(accountText));
+            return false;
+        }
+
+        return true;
+    });
 }
-#endif  /* HAS_INSTALL_ENV */
diff --git a/ui/qt5/accountpage.hh b/ui/qt5/accountpage.hh
index 9ca7577..cf1a4ff 100644
--- a/ui/qt5/accountpage.hh
+++ b/ui/qt5/accountpage.hh
@@ -20,11 +20,9 @@
 
 class AccountPage : public HorizonWizardPage {
 public:
-    AccountPage(QWidget *parent = nullptr);
+    explicit AccountPage(QWidget *parent = nullptr);
     bool isComplete() const override;
-#ifdef HAS_INSTALL_ENV
     bool validatePage() override;
-#endif
     std::array<UserAccountWidget *, 4> accountWidgets;
 };