Less version 590

Version 590 was released for beta testing on 3 June 2021.

These are the differences between version 581.2 and version 590:

• Make less able to read lesskey source files (deprecating lesskey).
• If XDG_CONFIG_HOME is set, find lesskey source file in $XDG_CONFIG_HOME/lesskey rather than $HOME/.lesskey.
• If XDG_DATA_HOME is set, find and store history file in $XDG_DATA_HOME/lesshst rather than $HOME/.lesshst.
• Add the --lesskey-src option.
• Add the --file-size option.
• With -F, if screen is resized to make file fit on one screen, don't exit.
• Fix bug which could leave terminal in mouse-reporting mode after exiting less.
• Fix bug which caused failure to respond to window resize.
• Fix backslash bug searching in tag file.