Re: [Bug-readline] vi-{cmd, ins}-mode-string and show-mode-in-prompt

[Rob Foehl]

On Sat, 9 Dec 2017, Chet Ramey wrote:

> So the problem is simply that you don't like the default strings in
> bash-4.3?

Well, subjectively, yes.  There's a difference between "don't like" and 
"won't work in the larger context of complex prompts", though.

> If this is a serious problem, move the setting of the variable into the
> bash startup files, where you can run the appropriate `bind' command
> based on the values of $BASH_VERSION and $BASH_VERSINFO.

That'd work for bash, but not other readline consumers.

> Not exactly.  The documentation is garbled, but it's simply wrong to
> assume that the behavior of show-mode-in-prompt being a toggle to turn
> the behavior on and off would have changed between bash-4.3 and bash-4.4
> without me noting the change in the change log. The documentation is
> obviously in error, but the desired behavior is that show-mode-in-prompt
> toggle the display of the mode characters (4.3) or mode strings (4.4).

The documentation doesn't mention show-mode-in-prompt outside of its own 
description, and the man page doesn't mention the mode strings there, 
either.  Why would anyone unfamiliar with its history assume it's 
relevant?  I certainly didn't.  Regardless, the patch doesn't change the 
behavior of show-mode-in-prompt itself in any way.

On desirability: the default behavior of show-mode-in-prompt doesn't play 
well with complex prompts, and setting any of the mode string variables 
would seem to indicate intent that they be used, in which case 
show-mode-in-prompt is superfluous.  Does a use case exist for setting 
mode strings but not using them?

I've attached another version of the patch that's arguably more robust 
across mode changes with odd combinations of settings.

-Rob

readline-mode-strings-v2.patch
Description: Text document