fix crash when changing toolbar visibility with empty toolbar.tools

ChangeLog

@@ -1,5 +1,8 @@
  (Format: Year/Month/Day)
 Changes for 1.0.0:
+*07/09/07:
+   * Fix crash when changing toolbar visibility, #1786765 (Mark)
+     FbTk/MenuItem.cc
 *07/08/27:
    * Fix hardcoded Mod1, use ModKey() now (Mathias)
      Window.cc

src/FbTk/Menu.cc

@@ -506,7 +506,7 @@ void Menu::updateMenu(int active_index) {
 
 void Menu::show() {
 
-    if (isVisible() || !menuitems.size())
+    if (isVisible() || menuitems.empty())
         return;
 
     m_visible = true;

src/FbTk/MenuItem.cc

@@ -34,8 +34,11 @@
 namespace FbTk {
 
 void MenuItem::click(int button, int time) {
-    if (m_command.get() != 0)
-        m_command->execute();
+    if (m_command.get() != 0) {
+        // we need a local variable, since the command may destroy this object
+        RefCount<Command> tmp(m_command);
+        tmp->execute();
+    }
 }
 
 void MenuItem::drawLine(FbDrawable &draw, const MenuTheme &theme, size_t size,

src/FbTk/Subject.cc

@@ -64,7 +64,7 @@ void Subject::notify() {
     m_notify_mode = false;
 
     // remove dead observers
-    if (m_dead_observers.size()) {
+    if (!m_dead_observers.empty()) {
         std::for_each(m_dead_observers.begin(),
                       m_dead_observers.end(),
                       std::bind1st(std::mem_fun(&Subject::detach), this));

src/MenuCreator.cc

@@ -325,7 +325,7 @@ static void translateMenuItem(Parser &parse, ParseItem &pitem, FbTk::StringConve
         if (submenu == 0)
             return;
 
-        if (str_cmd.size())
+        if (!str_cmd.empty())
             submenu->setLabel(str_cmd);
         else
             submenu->setLabel(str_label);

src/Remember.cc

@@ -387,7 +387,7 @@ int Remember::parseApp(ifstream &file, Application &app, string *first_line) {
 
             bool had_error = false;
 
-            if (!str_key.size())
+            if (str_key.empty())
                 continue; //read next line
             if (strcasecmp(str_key.c_str(), "Workspace") == 0) {
                 unsigned int w;

src/Toolbar.cc

@@ -412,7 +412,7 @@ void Toolbar::reconfigure() {
 
         m_tools = tools; // copy values
 
-        if (m_tools.size()) {
+        if (!m_tools.empty()) {
             // make lower case
             transform(m_tools.begin(), m_tools.end(),
                       m_tools.begin(),