fixed bug where scrolling to the bottom of a textbox wouldn't work properly

src/widgets/scrollarea.cpp

@@ -76,6 +76,11 @@ unsigned scrollarea::get_position() const
 	return scrollbar_.get_position();
 }
 
+unsigned scrollarea::get_max_position() const
+{
+	return scrollbar_.get_max_position();
+}
+
 void scrollarea::set_position(unsigned pos)
 {
 	scrollbar_.set_position(pos);

src/widgets/scrollarea.hpp

@@ -42,6 +42,7 @@ protected:
 	unsigned scrollbar_width() const;
 
 	unsigned get_position() const;
+	unsigned get_max_position() const;
 	void set_position(unsigned pos);
 	void adjust_position(unsigned pos);
 	void move_position(int dep);

src/widgets/scrollbar.cpp

@@ -78,9 +78,14 @@ unsigned scrollbar::get_position() const
 	return grip_position_;
 }
 
+unsigned scrollbar::get_max_position() const
+{
+	return full_height_ - grip_height_;
+}
+
 void scrollbar::set_position(unsigned pos)
 {
-	if (pos > full_height_ - grip_height_)
+	if (int(pos) > full_height_ - grip_height_)
 		pos = full_height_ - grip_height_;
 	if (pos == grip_position_)
 		return;
@@ -92,9 +97,9 @@ void scrollbar::set_position(unsigned pos)
 
 void scrollbar::adjust_position(unsigned pos)
 {
-	if (pos < grip_position_)
+	if (int(pos) < grip_position_)
 		set_position(pos);
-	else if (pos >= grip_position_ + grip_height_)
+	else if (int(pos) >= grip_position_ + grip_height_)
 		set_position(pos - (grip_height_ - 1));
 }
 
@@ -109,7 +114,7 @@ void scrollbar::move_position(int dep)
 
 void scrollbar::set_shown_size(unsigned h)
 {
-	if (h > full_height_)
+	if (int(h) > full_height_)
 		h = full_height_;
 	if (h == grip_height_)
 		return;

src/widgets/scrollbar.hpp

@@ -40,6 +40,8 @@ public:
 	///  is at the top, and (full_size - shown_size) if it is at the bottom.
 	unsigned get_position() const;
 
+	unsigned get_max_position() const;
+
 	/// Used to manually update the scrollbar.
 	void set_position(unsigned pos);
 

src/widgets/textbox.cpp

@@ -202,7 +202,7 @@ bool textbox::editable() const
 
 void textbox::scroll_to_bottom()
 {
-	set_position((unsigned)-1);
+	set_position(get_max_position());
 }
 
 void textbox::set_wrap(bool val)