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

[Juri Linkov]

> Here are two recipes (from emacs -Q) that seem to be bugs in Isearch:

Thanks for recipes.

> --------------------------------------------
> 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?

> --------------------------------------------
> 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'.