Subject: Re: bug#10113: 24.0.91; Isearch & `M-e'

From: Dani Moncayo <[email-masked]>
Date: Wed, 23 Nov 2011 09:02:27 +0100

>> --------------------------------------------
>> First case:
>> 1. Write the text "buffer buffeR".
>> 2. Type "C-a C-s b u f f e R M-e DEL RET".
>> --> Here the _current_ match should be the first "buffe", but it's the
>> second one.
>
> Why do think Isearch should go back to the first match without the user
> typing `C-r C-r' explicitly?

Because, removing the final "R" via minibuffer should be equivalent to
do it directly by typing DEL (just after the "R").  After all, the
final situation is the same in both cases:
* Search string = "buffer".
* Starting point = just before "buffer".

IOW, after editing the search string in the minibuffer, the Isearch
should be re-started from the beginning, using the new (edited) search
string.

>> --------------------------------------------
>> Second case:
>> 1. Write the text "buffer buffeR".
>> 2. Type "C-a C-s b u f f e R M-e DEL r RET".
>> --> Here both words should be matched, but only the first one is.
>
> Actually this is unrelated to `isearch-edit-string'.
> The first time you type an upper-case letter,
> Isearch switches to case-sensitive mode.
> You can observe this effect with the following case:
>
> 1. Write the text "buffer buffeR buffeRr buffeRR".
> 2. Type "C-a C-s b u f f e R r M-c".
>
> After you type the first upper-case letter `R', Isearch switches
> to case-sensitive mode, and after typing the next lower-case `r'
> Isearch doesn't match "buffeRR".  It does that only when you
> switch back to case-insensitive search mode by typing `M-c'.

In this second case, my reasoning is analogous: Changing the final "R"
with a "r" via minibuffer should be equivalent to doing that directly
(typing "DEL r" just after the "R").

IOW, the case-sensitivity of the Isearch, when it's determined
_automatically_ (not by typing `M-c'), should be revised after editing
the search string in the minibuffer, to produce a result consistent
with the principle I said before.

-- 
Dani Moncayo