[LyX/master] Add a move constructor to Inset

[Jean-Marc Lasgouttes]

commit 874928f4a4370d8b7b8092df33f4436a0f52e7f7
Author: Jean-Marc Lasgouttes <lasgouttes at lyx.org>
Date:   Mon Jul 12 11:55:19 2021 +0200

    Add a move constructor to Inset
    
    Does not change much, but Coverity complains about it. Let's see if
    this allows Inset's child classes to grow their own move constructor.
    
    Also some whitespace.
---
 src/insets/Inset.h |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/insets/Inset.h b/src/insets/Inset.h
index 4396c9b..0d69698 100644
--- a/src/insets/Inset.h
+++ b/src/insets/Inset.h
@@ -350,8 +350,8 @@ public:
 	/// Appends a potentially abbreviated version of the inset to
 	/// \param str. Intended for use by the TOC.
 	virtual void forOutliner(docstring & str,
-							 size_t const maxlen = TOC_ENTRY_LENGTH,
-							 bool const shorten = true) const;
+	                         size_t const maxlen = TOC_ENTRY_LENGTH,
+	                         bool const shorten = true) const;
 
 	/// Can a cursor be put in there ?
 	/// Forced to false for insets that have hidden contents, like
@@ -631,7 +631,8 @@ public:
 protected:
 	/// Constructors
 	Inset(Buffer * buf) : buffer_(buf) {}
-	Inset(Inset const &) : buffer_(0) {}
+	Inset(Inset const &) : buffer_(nullptr) {}
+	Inset(Inset const &&) : buffer_(nullptr) {}
 
 	/// replicate ourselves
 	friend class InsetList;