[Patch] Fix crash in rowpainter.C: paint

[Abdelrazak Younes]

Hello,

I came across this bug while playing with the painting. As the emptyness 
check is obviously correct I guess I will have no objection but I am 
asking anyway because I am good boy.

Any objection?

Abdel.
Index: rowpainter.C
===================================================================
--- rowpainter.C        (revision 14359)
+++ rowpainter.C        (working copy)
@@ -797,11 +797,14 @@
        static PainterInfo nullpi(pi.base.bv, nop);
        int const ww = pi.base.bv->workHeight();
 
+       theCoords.parPos()[&text][pit] = Point(x, y);
+
        Paragraph const & par = text.paragraphs()[pit];
+       if (par.rows().empty())
+               return;
 
        RowList::const_iterator const rb = par.rows().begin();
        RowList::const_iterator const re = par.rows().end();
-       theCoords.parPos()[&text][pit] = Point(x, y);
 
        y -= rb->ascent();
        lyx::size_type rowno(0);