Fix picking a gender and init randomly

Picking a gender was not working because the radio buttons weren't
synchronized with the internal variable holding the information. Discard
the internal variable and use the buttons as the source of truth.
Always make sure that one of the buttons is selected. Pick one randomly
on startup, as choosing one would be offensive towards half of
humankind.

Reported by Hawk on Discord.

client/dialogs.cpp

@@ -17,6 +17,7 @@
 #include <QKeyEvent>
 #include <QPainter>
 #include <QRadioButton>
+#include <QRandomGenerator>
 #include <QVBoxLayout>
 #include <QtMath>
 // utility
@@ -389,7 +390,6 @@ races_dialog::races_dialog(struct player *pplayer, QWidget *parent)
 
   selected_nation = -1;
   selected_style = -1;
-  selected_sex = -1;
   setWindowTitle(_("Select Nation"));
   selected_nation_tabs->setRowCount(0);
   selected_nation_tabs->setColumnCount(1);
@@ -432,6 +432,9 @@ races_dialog::races_dialog(struct player *pplayer, QWidget *parent)
   qgroupbox_layout->addWidget(is_female, 2, 0);
   is_female->setText(_("Female"));
   is_male->setText(_("Male"));
+  // Select a default fairly
+  is_male->setChecked(QRandomGenerator::global()->generate() % 2 == 0);
+  is_female->setChecked(!is_male->isChecked());
   no_name->setLayout(qgroupbox_layout);
 
   description = new QTextEdit;
@@ -699,7 +702,8 @@ void races_dialog::nation_selected(const QItemSelection &selected,
   description->setPlainText(buf);
   leader_name->clear();
   if (client.conn.playing == tplayer) {
-    leader_name->addItem(client.conn.playing->name, true);
+    // Add username preserving gender information
+    leader_name->addItem(client.conn.playing->name, is_male->isChecked());
   }
   nation_leader_list_iterate(
       nation_leaders(nation_by_number(selected_nation)), pleader)
@@ -753,11 +757,9 @@ void races_dialog::leader_selected(int index)
   if (leader_name->itemData(index).toBool()) {
     is_male->setChecked(true);
     is_female->setChecked(false);
-    selected_sex = 0;
   } else {
     is_male->setChecked(false);
     is_female->setChecked(true);
-    selected_sex = 1;
   }
 }
 
@@ -773,10 +775,7 @@ void races_dialog::ok_pressed()
     return;
   }
 
-  if (selected_sex == -1) {
-    output_window_append(ftc_client, _("You must select your sex."));
-    return;
-  }
+  fc_assert_ret(is_male->isChecked() || is_female->isChecked());
 
   if (selected_style == -1) {
     output_window_append(ftc_client, _("You must select your style."));
@@ -795,7 +794,7 @@ void races_dialog::ok_pressed()
   }
   ln_bytes = leader_name->currentText().toUtf8();
   dsend_packet_nation_select_req(&client.conn, player_number(tplayer),
-                                 selected_nation, selected_sex,
+                                 selected_nation, is_male->isChecked(),
                                  ln_bytes.data(), selected_style);
   close();
   deleteLater();

client/dialogs.h

@@ -156,7 +156,6 @@ private slots:
 private:
   int selected_nation;
   int selected_style;
-  int selected_sex;
   struct player *tplayer;
   int last_index;
 };