[LyX/master] Try to avoid horizontal scrolling with wide insets.

[Jean-Marc Lasgouttes]

commit eb1e85b096cf3f9f546ad2e8cfe10bfc872ab6e4
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Tue Nov 3 10:01:05 2015 +0100

    Try to avoid horizontal scrolling with wide insets.
    
    There was a problem with end of paragraph markers. By design, wide insets 
choose their size without taking in account the marker. This should not lead to 
unneeded horizontal scrolling.
    
    Part of ticket #9807.

diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index 762fe78..9a9a77b 100644
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -3045,7 +3045,7 @@ void BufferView::checkCursorScrollOffset(PainterInfo & pi)
        int offset = d->horiz_scroll_offset_;
        int const MARGIN = 2 * theFontMetrics(d->cursor_.real_current_font).em()
                           + row.right_margin;
-       if (row.width() <= workWidth() - row.right_margin) {
+       if (row.right_x() <= workWidth() - row.right_margin) {
                // Row is narrower than the work area, no offset needed.
                offset = 0;
        } else {
@@ -3059,8 +3059,8 @@ void BufferView::checkCursorScrollOffset(PainterInfo & pi)
                // Correct the offset to make sure that we do not scroll too 
much
                if (offset < 0)
                        offset = 0;
-               if (row.width() - offset < workWidth() - row.right_margin)
-                       offset = row.width() - workWidth() + row.right_margin;
+               if (row.right_x() - offset < workWidth() - row.right_margin)
+                       offset = row.right_x() - workWidth() + row.right_margin;
        }
 
        //lyxerr << "cur_x=" << cur_x << ", offset=" << offset << ", row.wid=" 
<< row.width() << ", margin=" << MARGIN << endl;