ecode: Don't crash if the terminal could not initialize.

Closes issue SpartanJ/ecode#81.

src/modules/eterm/src/eterm/ui/uiterminal.cpp

@@ -39,8 +39,10 @@ bool UITerminal::isType( const Uint32& type ) const {
 }
 
 void UITerminal::draw() {
-	mTerm->setPosition( mScreenPosi.asFloat() );
-	mTerm->draw();
+	if ( mTerm ) {
+		mTerm->setPosition( mScreenPosi.asFloat() );
+		mTerm->draw();
+	}
 }
 
 UITerminal::UITerminal( const std::shared_ptr<TerminalDisplay>& terminalDisplay ) :
@@ -49,6 +51,8 @@ UITerminal::UITerminal( const std::shared_ptr<TerminalDisplay>& terminalDisplay
 	mVScroll( UIScrollBar::NewVertical() ),
 	mTerm( terminalDisplay ) {
 	mFlags |= UI_TAB_STOP;
+	if ( !terminalDisplay )
+		return;
 	mTerm->pushEventCallback( [&]( const TerminalDisplay::Event& event ) {
 		switch ( event.type ) {
 			case TerminalDisplay::EventType::TITLE: {
@@ -297,6 +301,8 @@ const std::shared_ptr<TerminalDisplay>& UITerminal::getTerm() const {
 }
 
 void UITerminal::scheduledUpdate( const Time& ) {
+	if ( !mTerm )
+		return;
 	mTerm->update();
 
 	if ( mTerm->isDirty() )

src/tools/ecode/terminalmanager.cpp

@@ -258,6 +258,15 @@ UITerminal* TerminalManager::createNewTerminal( const std::string& title, UITabW
 		mApp->termConfig().fontSize.asPixels( 0, Sizef(), mApp->getDisplayDPI() ), initialSize,
 		program, args, !workingDir.empty() ? workingDir : mApp->getCurrentWorkingDir(), 10000,
 		nullptr, mUseFrameBuffer );
+	if ( term->getTerm() == nullptr ) {
+		UIMessageBox* msgBox = UIMessageBox::New(
+			UIMessageBox::OK,
+			mApp->i18n( "feature_not_supported_in_os",
+						"This feature is not supported in this Operating System" ) );
+		msgBox->showWhenReady();
+		return nullptr;
+	}
+
 	term->getTerm()->getTerminal()->setAllowMemoryTrimnming( true );
 	auto ret = mApp->getSplitter()->createWidgetInTabWidget(
 		tabWidget, term, title.empty() ? mApp->i18n( "shell", "Shell" ).toUtf8() : title, true );