[LyX/master] repair Cursor::x_target mechanism (#10168)

[Guillaume Munch]

commit 4f3c3a794e36c3f53373ccdbd63c923660b892ff
Author: Guillaume Munch <g...@lyx.org>
Date:   Sun Mar 19 14:41:54 2017 +0100

    repair Cursor::x_target mechanism (#10168)
---
 src/Cursor.cpp |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/src/Cursor.cpp b/src/Cursor.cpp
index 758cef9..3fd2578 100644
--- a/src/Cursor.cpp
+++ b/src/Cursor.cpp
@@ -1906,10 +1906,13 @@ bool Cursor::upDownInText(bool up, bool & updateNeeded)
                int yo = bv().getPos(*this).y_;
                Cursor old = *this;
                // To next/previous row
+               // FIXME: the y position is often guessed wrongly across styles 
and
+               // insets, which leads to weird behaviour.
                if (up)
                        tm.editXY(*this, xo, yo - textRow().ascent() - 1);
                else
                        tm.editXY(*this, xo, yo + textRow().descent() + 1);
+               x_target_ = old.x_target_;
                clearSelection();
 
                // This happens when you move out of an inset.