Try to make sure that math insets have a properly set buffer_ member

Set the buffer of contents that is added to a MathData object through
MathData::insert() (both versions)
MathData::push_back()
asArray()

Also in math macros, initialize look_ with the relevant buffer.

This reduces the number of insets hat do not have a proper buffer.

See #13050 for discussion of this issue.

src/mathed/InsetMathMacroTemplate.cpp

@@ -394,7 +394,7 @@ void InsetNameWrapper::draw(PainterInfo & pi, int x, int y) const
 
 
 InsetMathMacroTemplate::InsetMathMacroTemplate(Buffer * buf)
-	: InsetMathNest(buf, 3), numargs_(0), argsInLook_(0), optionals_(0),
+	: InsetMathNest(buf, 3), look_(buf), numargs_(0), argsInLook_(0), optionals_(0),
 	  type_(MacroTypeNewcommand), redefinition_(false), lookOutdated_(true),
 	  premetrics_(false), labelBoxAscent_(0), labelBoxDescent_(0)
 {
@@ -405,8 +405,8 @@ InsetMathMacroTemplate::InsetMathMacroTemplate(Buffer * buf)
 InsetMathMacroTemplate::InsetMathMacroTemplate(Buffer * buf, docstring const & name, int numargs,
 	int optionals, MacroType type, vector<MathData> const & optionalValues,
 	MathData const & def, MathData const & display)
-	: InsetMathNest(buf, optionals + 3), numargs_(numargs), argsInLook_(numargs),
+	: InsetMathNest(buf, optionals + 3), look_(buf), numargs_(numargs),
-	  optionals_(optionals), optionalValues_(optionalValues),
+	  argsInLook_(numargs), optionals_(optionals), optionalValues_(optionalValues),
 	  type_(type), redefinition_(false), lookOutdated_(true),
 	  premetrics_(false), labelBoxAscent_(0), labelBoxDescent_(0)
 {
@@ -536,6 +536,8 @@ void InsetMathMacroTemplate::createLook(int args) const
 	look_.push_back(MathAtom(
 		new InsetDisplayLabelBox(buffer_, MathAtom(
 			new InsetMathWrapper(&cell(displayIdx()))), _("LyX"), *this)));
+
+	look_.setContentsBuffer();
 }
 
 

src/mathed/MathData.cpp

@@ -52,11 +52,18 @@ MathData::MathData(Buffer * buf, const_iterator from, const_iterator to)
 {}
 
 
+void MathData::setContentsBuffer()
+{
+	if (buffer_)
+		for (MathAtom & at : *this)
+			at.nucleus()->setBuffer(*buffer_);
+}
+
+
 void MathData::setBuffer(Buffer & b)
 {
 	buffer_ = &b;
-	for (MathAtom & at : *this)
+	setContentsBuffer();
-		at.nucleus()->setBuffer(b);
 }
 
 
@@ -78,6 +85,8 @@ void MathData::insert(size_type pos, MathAtom const & t)
 {
 	LBUFERR(pos <= size());
 	base_type::insert(begin() + pos, t);
+	if (buffer_)
+		operator[](pos)->setBuffer(*buffer_);
 }
 
 
@@ -85,6 +94,17 @@ void MathData::insert(size_type pos, MathData const & ar)
 {
 	LBUFERR(pos <= size());
 	base_type::insert(begin() + pos, ar.begin(), ar.end());
+	if (buffer_)
+		for (size_type i = 0 ; i < ar.size() ; ++i)
+			operator[](pos + i)->setBuffer(*buffer_);
+}
+
+
+void MathData::push_back(MathAtom const & t)
+{
+	base_type::push_back(t);
+	if (buffer_)
+		back()->setBuffer(*buffer_);
 }
 
 

src/mathed/MathData.h

@@ -59,7 +59,6 @@ public:
 	using base_type::clear;
 	using base_type::begin;
 	using base_type::end;
-	using base_type::push_back;
 	using base_type::pop_back;
 	using base_type::back;
 	using base_type::front;
@@ -85,6 +84,8 @@ public:
 	void insert(size_type pos, MathAtom const & at);
 	/// inserts multiple atoms at position pos
 	void insert(size_type pos, MathData const & ar);
+	/// inserts single atom at end
+	void push_back(MathAtom const & at);
 
 	/// erase range from pos1 to pos2
 	void erase(iterator pos1, iterator pos2);
@@ -187,8 +188,10 @@ public:
 	void updateMacros(Cursor * cur, MacroContext const & mc, UpdateType, int nesting);
 	///
 	void updateBuffer(ParIterator const &, UpdateType, bool const deleted = false);
-	///
+	/// Change associated buffer for this object and its contents
 	void setBuffer(Buffer & b);
+	/// Update assiociated buffer for the contents of the object
+	void setContentsBuffer();
 
 protected:
 	/// cached values for super/subscript placement

src/mathed/MathSupport.cpp

@@ -1102,6 +1102,9 @@ void asArray(docstring const & str, MathData & ar, Parse::flags pf)
 	bool macro = pf & Parse::MACRODEF;
 	if ((str.size() == 1 && quiet) || (!mathed_parse_cell(ar, str, pf) && quiet && !macro))
 		mathed_parse_cell(ar, str, pf | Parse::VERBATIM);
+
+	// set the buffer of the MathData contents
+	ar.setContentsBuffer();
 }