[LyX/master] Fixup 86bfa10a: add checks before updating bookmarks

[Jean-Marc Lasgouttes]

commit ac8948b8e00c4b517a117cc36b01b696def668c1
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Fri Mar 12 17:37:31 2021 +0100

    Fixup 86bfa10a: add checks before updating bookmarks
    
    When doing cut and paste, it can happen that inset_owner_ is null, or
    that the inset is not related to a buffer.
---
 src/Paragraph.cpp |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/Paragraph.cpp b/src/Paragraph.cpp
index 8ac87d3..6bf4ce3 100644
--- a/src/Paragraph.cpp
+++ b/src/Paragraph.cpp
@@ -835,8 +835,9 @@ void Paragraph::Private::insertChar(pos_type pos, char_type c,
 	speller_state_.increasePosAfterPos(pos);
 
 	// Update bookmarks
-	theSession().bookmarks().adjustPosAfterPos(inset_owner_->buffer().fileName(),
-	                                           id_, pos, 1);
+	if (inset_owner_ && inset_owner_->isBufferValid())
+		theSession().bookmarks().adjustPosAfterPos(inset_owner_->buffer().fileName(),
+	                                               id_, pos, 1);
 }
 
 
@@ -922,8 +923,9 @@ bool Paragraph::eraseChar(pos_type pos, bool trackChanges)
 	d->speller_state_.refreshLast(size());
 
 	// Update bookmarks
-	theSession().bookmarks().adjustPosAfterPos(d->inset_owner_->buffer().fileName(),
-	                                           d->id_, pos, -1);
+	if (d->inset_owner_ && d->inset_owner_->isBufferValid())
+		theSession().bookmarks().adjustPosAfterPos(d->inset_owner_->buffer().fileName(),
+	                                               d->id_, pos, -1);
 
 	return true;
 }