Re: Problems with ANSI colors in shell mode in Emacs 21.2.95.

[Andreas Schwab]

Lute Kamstra <address@hidden> writes:

|> Richard Stallman <address@hidden> writes:
|> 
|> >     I tested a few old pretests and found out that the problem first
|> >     occurred in Emacs 21.2.91.  In Emacs 21.2.90, the shell prompt looks
|> >     fine.
|> > 
|> > Can you identify the Emacs change that did it?
|> 
|> Yes.  The change in shell.el is causing the change in behavior.  With
|> Emacs 21.2.91, a new user option is introduced in Emacs.  Here's the
|> changelog entry:
|> 
|> ,----
|> | 2002-07-30  Andreas Schwab  <address@hidden>
|> | 
|> |    * shell.el (explicit-bash-args): New user option.
|> `----
|> 
|> The user option looks like this:
|> 
|> ,----[ shell.el; lines 278-284 ]
|> | (defcustom explicit-bash-args
|> |     ;; Tell bash not to use readline.
|> |     '("--noediting" "-i")
|> |   "*Args passed to inferior shell by M-x shell, if the shell is bash.
|> | Value is a list of strings, which may be nil."
|> |   :type '(repeat (string :tag "Argument"))
|> |   :group 'shell)
|> `----
|> 
|> With my setup, this causes bash to be started with the "--noediting"
|> option (in Emacs 21.2.91), while this was not the case before (in
|> Emacs 21.2.90).  The bash man pages say:
|> 
|> ,----[ man bash ]
|> |        --noediting
|> |               Do not use the GNU readline library to read command
|> |               lines when the shell is interactive.
|> |  
|> `----
|> 
|> I'm not sure what Andreas Schwab's idea behind this change was.

This change is needed to get control characters passed properly to bash.
Otherwise they are intercepted by readline, which is not what we want.

|> then the ^A and ^B characters don't appear anymore and things work
|> fine again as they did in Emacs 21.2.90.

Do you have a custom $PS1?  Does it contains empty \[\] sequences?  Then
this is a bug in bash.

Andreas.

-- 
Andreas Schwab, SuSE Labs, address@hidden
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