[LyX/master] Fixup 283ac91a: Forgotten test for null pointer

[Jean-Marc Lasgouttes]

commit 051da4ba252e5ef1073ba85de3ff1f197ac061d5
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Wed Apr 3 12:13:13 2019 +0200

    Fixup 283ac91a: Forgotten test for null pointer
---
 src/TextMetrics.cpp |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/TextMetrics.cpp b/src/TextMetrics.cpp
index 6ce580c..d0b9071 100644
--- a/src/TextMetrics.cpp
+++ b/src/TextMetrics.cpp
@@ -992,7 +992,7 @@ bool TextMetrics::breakRow(Row & row, int const 
right_margin) const
                        // - a display inset followed by a end label.
                        need_new_row =
                                par.isNewline(i)
-                               || (inset->display() && i + 1 == end
+                               || (inset && inset->display() && i + 1 == end
                                    && text_->getEndLabel(row.pit()) != 
END_LABEL_NO_LABEL);
                        ++i;
                        break;