bug#40185: #40185: 28.0.50; Emacs Calc selection of a sub-formula doesn't highlight it

[Mattias Engdegård]

23 mars 2020 kl. 20.06 skrev Narendra Joshi <narendraj9@gmail.com>:

> Can you please help me
> understand what exactly the issue was and how declaring the variable
> fixed it? I see that it is `defvar`ed  in `calc-ext.el`.

'defvar' without an initial value is a declaration scoped to the surrounding 
lexical scope (or file, if at top level). It appears that calc.el does not 
require calc-ext, so that math-comp-selected was assumed to be lexical where it 
was bound in math-format-stack-value. This caused it to have the wrong number 
further down the call tree (in math-comp-to-string-flat, I think).

In Emacs 26 and earlier, calc.el used dynamic binding.

Thanks for verifying! Patch pushed to emacs-27.