[LyX/master] Fix InsetBox::contentAlignment()

[Juergen Spitzmueller]

commit de67b68b1dc140321e5d0e2e6b4507c972703744
Author: Juergen Spitzmueller <sp...@lyx.org>
Date:   Fri May 11 15:11:06 2018 +0200

    Fix InsetBox::contentAlignment()
    
    Some cases where alignment is possible were missing.
    
    Candidate for 2.3.x.
---
 src/insets/InsetBox.cpp |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/src/insets/InsetBox.cpp b/src/insets/InsetBox.cpp
index 2219c23..7711277 100644
--- a/src/insets/InsetBox.cpp
+++ b/src/insets/InsetBox.cpp
@@ -238,7 +238,9 @@ ColorCode InsetBox::backgroundColor(PainterInfo const &) 
const
 
 LyXAlignment InsetBox::contentAlignment() const
 {
-       if (!params_.use_makebox)
+       // Custom horizontal alignment is only allowed with a fixed width
+       // and if either makebox or no inner box are used
+       if (params_.width.empty() || !(params_.use_makebox || 
!params_.inner_box))
                return LYX_ALIGN_NONE;
 
        // The default value below is actually irrelevant