[Bug-readline] Cannot use M-<key> bindings in incremental search

[Davor Cubranic]

Readline 6.1 on KUbuntu 10.04 (Lucid), package libreadline6 (6.1-1)

If I bind incremental search to a M-<key>, and start the search, 
Readline does not interpret correctly subsequent presses of the key. 
Instead of showing the next match, what happens is that the search is 
restarted, with the search string reset to empty.

My .inputrc:

"\es": reverse-search-history # Meta-s
"\eS": forward-search-history # Meta-S

Could this be because the lookup of the key in _rl_isearch_dispatch 
(isearch.c:340) does not match for bindings involving Meta because the 
input character 'c' does not map to an ISFUNC in the current _rl_keymap? 
(I notice that at bind.c:377, readline will switch to using a different 
keymap for keys involving meta/escape. This does not seem to happen in 
the case of isearch.)

Readline variable settings:
    $ bind -v
    set bind-tty-special-chars on
    set blink-matching-paren on
    set byte-oriented off
    set completion-ignore-case on
    set convert-meta off
    set disable-completion off
    set echo-control-characters on
    set enable-keypad off
    set enable-meta-key on
    set expand-tilde off
    set history-preserve-point off
    set horizontal-scroll-mode off
    set input-meta on
    set mark-directories on
    set mark-modified-lines off
    set mark-symlinked-directories on
    set match-hidden-files on
    set meta-flag on
    set output-meta on
    set page-completions on
    set prefer-visible-bell on
    set print-completions-horizontally off
    set revert-all-at-newline off
    set show-all-if-ambiguous off
    set show-all-if-unmodified off
    set skip-completed-text off
    set visible-stats off
    set bell-style none
    set comment-begin #
    set completion-prefix-display-length 0
    set completion-query-items 100
    set editing-mode emacs
    set history-size 200
    set isearch-terminators \C-g
    set keymap emacs

Thanks,

Davor