bug#3746: M-r in comint mode should use isearch

[Juri Linkov]

> When using the minibuffer for example doing:
>
> M-x
> then
> C-r
> will use isearch to search the history.  This is nice because it shows
> the items that are matched.
>
> M-r should to the same thing when used in comint, right now it's hard
> to tell if it matches anything before typing RET

Do you mean implementing a bash-like history isearch
in comint/shell modes?  I think it would be nice.
But maybe M-r is not the best key to start a shell history
isearch in the comint buffer.  In the minibuffer M-r keeps
its old functionality, and C-s is used to isearch the
minibuffer history.

It seems we can't use C-s in the comint buffer to isearch the
shell history because searching in the output is useful as well.
Maybe we should let C-s to isearch the shell history from the M-r
minibuffer instead of the minibuffer history of the previous M-r input?

-- 
Juri Linkov
http://www.jurta.org/emacs/