More correct handling of SIGHUP while suspended

Fixes #833

src/main.cc

@@ -357,6 +357,7 @@ std::unique_ptr<UserInterface> create_local_ui(UIType ui_type)
             local_ui = this;
             m_old_sighup = set_signal_handler(SIGHUP, [](int) {
                 ClientManager::instance().remove_client(*local_client, false);
+                static_cast<LocalUI*>(local_ui)->on_sighup();
             });
 
             m_old_sigtstp = set_signal_handler(SIGTSTP, [](int) {
@@ -373,9 +374,8 @@ std::unique_ptr<UserInterface> create_local_ui(UIType ui_type)
 
                     raise(SIGTSTP);
 
-                    sigprocmask(SIG_SETMASK, &old_mask, nullptr);
-
                     set_signal_handler(SIGTSTP, current);
+                    sigprocmask(SIG_SETMASK, &old_mask, nullptr);
                 }
                 else
                     convert_to_client_pending = true;

src/ncurses_ui.cc

@@ -480,8 +480,19 @@ void NCursesUI::check_resize(bool force)
     werase(curscr);
 }
 
+void NCursesUI::on_sighup()
+{
+    set_signal_handler(SIGWINCH, SIG_DFL);
+    set_signal_handler(SIGCONT, SIG_DFL);
+
+    m_window = nullptr;
+}
+
 bool NCursesUI::is_key_available()
 {
+    if (not m_window)
+        return false;
+
     check_resize();
 
     wtimeout(m_window, 0);
@@ -492,7 +503,6 @@ bool NCursesUI::is_key_available()
     return c != ERR;
 }
 
-
 Key NCursesUI::get_key()
 {
     check_resize();

src/ncurses_ui.hh

@@ -59,6 +59,10 @@ public:
         DisplayCoord pos;
         DisplayCoord size;
     };
+
+protected:
+    void on_sighup();
+
 private:
     void check_resize(bool force = false);
     void redraw();