Make hypertext and textarea have proper scroll event propagation. (#10860)

Author: v-rob

games/devtest/mods/testformspec/formspec.lua

@@ -220,6 +220,8 @@ local scroll_fs =
 		"tooltip[0,11;3,2;Buz;#f00;#000]"..
 		"box[0,11;3,2;#00ff00]"..
 		"hypertext[3,13;3,3;;" .. hypertext_basic .. "]" ..
+		"hypertext[3,17;3,3;;Hypertext with no scrollbar\\; the scroll container should scroll.]" ..
+		"textarea[3,21;3,1;textarea;;More scroll within scroll]" ..
 		"container[0,18]"..
 			"box[1,2;3,2;#0a0a]"..
 			"scroll_container[1,2;3,2;scrbar2;horizontal;0.06]"..

src/gui/guiEditBox.cpp

@@ -787,6 +787,7 @@ bool GUIEditBox::processMouse(const SEvent &event)
 			s32 pos = m_vscrollbar->getPos();
 			s32 step = m_vscrollbar->getSmallStep();
 			m_vscrollbar->setPos(pos - event.MouseInput.Wheel * step);
+			return true;
 		}
 		break;
 	default:

src/gui/guiHyperText.cpp

@@ -1088,7 +1088,7 @@ bool GUIHyperText::OnEvent(const SEvent &event)
 		if (event.MouseInput.Event == EMIE_MOUSE_MOVED)
 			checkHover(event.MouseInput.X, event.MouseInput.Y);
 
-		if (event.MouseInput.Event == EMIE_MOUSE_WHEEL) {
+		if (event.MouseInput.Event == EMIE_MOUSE_WHEEL && m_vscrollbar->isVisible()) {
 			m_vscrollbar->setPos(m_vscrollbar->getPos() -
 					event.MouseInput.Wheel * m_vscrollbar->getSmallStep());
 			m_text_scrollpos.Y = -m_vscrollbar->getPos();