[LyX/master] Fix crash in info inset dialog apply (bug 9896)

[Georg Baum]

commit 92573c9ddcc8dd367fc9f681ca4910d4deb98e29
Author: Georg Baum <b...@lyx.org>
Date:   Thu Dec 10 20:21:20 2015 +0100

    Fix crash in info inset dialog apply (bug 9896)
    
    posBackward() is the exact inverse of posForward(), not backwardPos().

diff --git a/src/BufferView.cpp b/src/BufferView.cpp
index 06ea9ea..e237a63 100644
--- a/src/BufferView.cpp
+++ b/src/BufferView.cpp
@@ -2202,7 +2202,7 @@ void BufferView::mouseEventDispatch(FuncRequest const & 
cmd0)
                // cursor in front of the inset.
                if (inset->hasSettings() &&
                    cur.nextInset() != inset && cur.prevInset() == inset)
-                       cur.backwardPos();
+                       cur.posBackward();
        }
 
        // Put anchor at the same position.