Force a Buffer * argument to MathData constructor
In order to ensure that MathData objects have a valid buffer, the
default MathData() constructor is deleted. This means that a buffer
shall be specified for each MathData object created.
This is fairly mechanical, actually. In particular, in most
InsetMathXxx cases, in MathData and in MathParser, the available
buffer_ member is used.
More specific cases:
- lyxfind.cpp takes the buffer from the Cursor
- calls to vector<MathData>::resize take an additional
MathData(buffer_) parameter. There are cases where resize actually
remove cells, and in this case clear() or even erase() have been
used.
- in InsetMathMacroTemplate, the optional parameters of the
constructors cannot be allowed anymore (a default value cannot
depend on another parameter). Therefore there a now two constructors
instead.
- in MathAutoCorrect.cpp, the MathData objects are not bound to a
buffer, so that std::nullptr is used instead.
- in MathExtern, use a buffer when one is specified, std::nulptr
instead.
(cherry picked from commit
57d713065545ac53a62a641d12a8b8c2c62c22fc)