Fix height of cursor inside insets

It turns out that Cursor::getFont() does not return a fully realized
font in some cases. This patch uses real_current_font instead, which
seems better anyway.

I suspect that all uses of getFont() should be removed, but this is
not code that I know well.

Fixes bug #10478.
(cherry picked from commit b099d9ae15)

src/BufferView.cpp

@@ -2878,7 +2878,7 @@ bool BufferView::paragraphVisible(DocIterator const & dit) const
 void BufferView::cursorPosAndHeight(Point & p, int & h) const
 {
 	Cursor const & cur = cursor();
-	Font const font = cur.getFont();
+	Font const font = cur.real_current_font;
 	frontend::FontMetrics const & fm = theFontMetrics(font);
 	int const asc = fm.maxAscent();
 	int const des = fm.maxDescent();

src/Cursor.cpp

@@ -2201,6 +2201,7 @@ Font Cursor::getFont() const
 	// The logic here should more or less match to the
 	// Cursor::setCurrentFont logic, i.e. the cursor height should
 	// give a hint what will happen if a character is entered.
+	// FIXME: this is not the case, what about removing this method ? (see #10478).
 
 	// HACK. far from being perfect...
 

src/frontends/qt4/GuiWorkArea.cpp

@@ -1274,6 +1274,7 @@ void GuiWorkArea::inputMethodEvent(QInputMethodEvent * e)
 	GuiPainter pain(d->screen_, pixelRatio());
 	d->buffer_view_->updateMetrics();
 	d->buffer_view_->draw(pain);
+	// FIXME: shall we use real_current_font here? (see #10478)
 	FontInfo font = d->buffer_view_->cursor().getFont().fontInfo();
 	FontMetrics const & fm = theFontMetrics(font);
 	int height = fm.maxHeight();

status.22x

@@ -123,7 +123,10 @@ What's new
 
 - Allow using colors supported by xcolor inside mathed (bug 10417).
 
-- Change description of "frame of button" color to "button frame" (bug 10135).
+- Change description of "frame of button" color to "button frame" (bug
+  10135).
+
+- Fix height of cursor inside insets (bug 10478).
 
 
 * INTERNALS