[LyX/2.2.x] Set boundary correctly in getPosNearX

[Jean-Marc Lasgouttes]

commit ff9732462114b939f330f88689ba36d61fde3b8f
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Thu Apr 6 15:05:19 2017 +0200

    Set boundary correctly in getPosNearX
    
    The code that looks whether neighbor block has a different direction
    should look to the left or to the right depending on the direction of
    the current block.
    
    Fixes part of bug #10569
    
    (cherry picked from commit e3d252cd6256b32745b93c0cb0fd5170f448f91c)
---
 src/TextMetrics.cpp |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/TextMetrics.cpp b/src/TextMetrics.cpp
index 0629c1e..68fcb3c 100644
--- a/src/TextMetrics.cpp
+++ b/src/TextMetrics.cpp
@@ -1181,8 +1181,10 @@ pos_type TextMetrics::getPosNearX(Row const & row, int & 
x,
                 * how boundary helps here.
                 */
                else if (pos == cit->endpos
-                        && cit + 1 != row.end()
-                        && cit->isRTL() != (cit + 1)->isRTL())
+                        && ((!cit->isRTL() && cit + 1 != row.end()
+                             && (cit + 1)->isRTL())
+                            || (cit->isRTL() && cit != row.begin()
+                                && !(cit - 1)->isRTL())))
                        boundary = true;
        }