bug#50409: describe-variable says variable was introduced in two different versions

[Stefan Kangas]

Severity: minor

describe-variable is saying that 'tab-first-completion' was introduced
in both 27.1 and 28.1.

Steps to reproduce:

0. emacs -Q
1. C-h v describe-variable RET

The help buffer now shows:

tab-first-completion is a variable defined in ‘indent.el’.

Its value is nil

  You can customize this variable.
  This variable was introduced, or its default value was changed, in
  version 27.1 of Emacs.
  Probably introduced at or before Emacs version 28.1.