Sync readline/ to version 7.0 alpha

This patch syncs our upstream copy of readline from version 6.2 to the
latest version, 7.0 alpha (released July 10 2015).

I essentially copied what was done the last time readline was synced,
when Jan updated to readline 6.2 in 2011:
http://sourceware.org/ml/gdb-patches/2011-05/msg00003.html

Procedure:

1. I extracted the readline-7.0-alpha tarball on top of readline/.
2. I deleted all the new files under doc/ that were deliberately omitted
   before.
3. I regenerated readline/configure and readline/examples/rlfe/configure
   using autoconf 2.64.  No other configure files need regenerating.
4. I updated the function gdb_printable_part in completer.c with a
   trivial change made to the readline function it is based off of,
   printable_part in readline/complete.c.  There is more work to be done in
   completer.c to sync it with readline/complete.c, but it is non-trivial
   and should probably be done separately anyway.

Local patches that had to be reapplied:

    None.  readline 7.0 alpha contains all of our local readline
    patches.

New files in readline/:

    colors.{c,h}
    examples/{hist_erasedups,hist_purgecmd,rl-callbacktest,rlbasic}.c
    parse-colors.{c,h}
    readline.pc.in
    configure.ac

Deleted files in readline/:

    configure.in

Regressions:

After the sync there is one testsuite regression, the test
"signal SIGINT" in gdb.gdb/selftest.exp which now FAILs.  Previously,
the readline 6.2 SIGINT handler would temporarily reinstall the
underlying application's SIGINT handler and immediately re-raise SIGINT
so that the orginal handler gets invoked.  But now (since readline 6.3)
its SIGINT handler does not re-raise SIGINT or directly invoke the
original handler; it now sets a flag marking that SIGINT was raised, and
waits until readline explicitly has control to call the application's
SIGINT handler.  Anyway, because SIGINT is no longer re-raised from
within readline's SIGINT handler, doing "signal SIGINT" with a stopped
inferior gdb process will no longer resume and then immediately stop the
process (since there is no 2nd SIGINT to immediately catch).  Instead,
the inferior gdb process will now just print "Quit" and continue to run.
So with this commit, this particular test case is adjusted to reflect
this change in behavior (we now have to send a 2nd SIGINT manually to
stop it).

Aside from this one testsuite regression, I personally noticed no
regression in user-visible behavior.  Though I only tested on x86_64
and on i686 Debian Stretch.

Getting this kind of change in at the start of the GDB 7.11 development
cycle will allow us to get a lot of passive testing from developers and
from bleeding-edge users.

readline/ChangeLog.gdb:

	Import readline 7.0 alpha
	* configure: Regenerate.
	* examples/rlfe/configure: Regenerate.

gdb/ChangeLog:

	* completer.c (gdb_printable_part): Sync with readline function
	it is based off of.

gdb/testsuite/ChangeLog:

	* gdb.gdb/selftest.exp (test_with_self): Update test to now
	expect the GDB inferior to no longer immediately stop after
	being resumed with "signal SIGINT".

1 files changed, 277 insertions, 14 deletions

diff --git a/readline/NEWS b/readline/NEWS
index 0ec6e09..11ac0e3 100644
--- a/readline/NEWS
+++ b/readline/NEWS
@@ -1,19 +1,282 @@
-This is a terse description of the new features added to readline-6.2 since
-the release of readline-6.1.
+This is a terse description of the new features added to readline-7.0 since
+the release of readline-6.3.
 
-a.  The history library does not try to write the history filename in the
-    current directory if $HOME is unset.  This closes a potential security
-    problem if the application does not specify a history filename.
+New Features in Readline
 
-b.  New bindable variable `completion-display-width' to set the number of
-    columns used when displaying completions.
+a.  The history truncation code now uses the same error recovery mechansim as
+    the history writing code, and restores the old version of the history file
+    on error.  The error recovery mechanism handles symlinked history files.
 
-c.  New bindable variable `completion-case-map' to cause case-insensitive
-    completion to treat `-' and `_' as identical.
+b.  There is a new bindable variable, `enable-bracketed-paste', which enables
+    support for a terminal's bracketed paste mode.
 
-d.  There are new bindable vi-mode command names to avoid readline's case-
-    insensitive matching not allowing them to be bound separately.
+c.  The editing mode indicators can now be strings and are user-settable
+    (new `emacs-mode-string', `vi-cmd-mode-string' and `vi-ins-mode-string'
+    variables).  Mode strings can contain invisible character sequences.
+    Setting mode strings to null strings restores the defaults.
 
-e.  New bindable variable `menu-complete-display-prefix' causes the menu
-    completion code to display the common prefix of the possible completions
-    before cycling through the list, instead of after.
+d.  Prompt expansion adds the mode string to the last line of a multi-line
+    prompt (one with embedded newlines).
+
+e.  There is a new bindable variable, `colored-completion-prefix', which, if
+    set, causes the common prefix of a set of possible completions to be
+    displayed in color.
+
+f.  There is a new bindable command `vi-yank-pop', a vi-mode version of emacs-
+    mode yank-pop.
+
+g.  The redisplay code underwent several efficiency improvements for multibyte
+    locales.
+
+h.  The insert-char function attempts to batch-insert all pending typeahead
+    that maps to self-insert, as long as it is coming from the terminal.
+
+i.  rl_callback_sigcleanup: a new application function that can clean up and
+    unset any state set by readline's callback mode.  Intended to be used
+    after a signal.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to readline-6.3 since
+the release of readline-6.2.
+
+New Features in Readline
+
+a.  Readline is now more responsive to SIGHUP and other fatal signals when
+    reading input from the terminal or performing word completion but no
+    longer attempts to run any not-allowable functions from a signal handler
+    context.
+
+b.  There are new bindable commands to search the history for the string of
+    characters between the beginning of the line and the point
+    (history-substring-search-forward, history-substring-search-backward)
+
+c.  Readline allows quoted strings as the values of variables when setting
+    them with `set'.  As a side effect, trailing spaces and tabs are ignored
+    when setting a string variable's value.
+
+d.  The history library creates a backup of the history file when writing it
+    and restores the backup on a write error.
+
+e.  New application-settable variable: rl_filename_stat_hook: a function called
+    with a filename before using it in a call to stat(2).  Bash uses it to
+    expand shell variables so things like $HOME/Downloads have a slash
+    appended.
+
+f.  New bindable function `print-last-kbd-macro', prints the most-recently-
+    defined keyboard macro in a reusable format.
+
+g.  New user-settable variable `colored-stats', enables use of colored text
+    to denote file types when displaying possible completions (colored analog
+    of visible-stats).
+
+h.  New user-settable variable `keyseq-timout', acts as an inter-character
+    timeout when reading input or incremental search strings.
+
+i.  New application-callable function: rl_clear_history. Clears the history list
+    and frees all readline-associated private data.
+
+j.  New user-settable variable, show-mode-in-prompt, adds a characters to the
+    beginning of the prompt indicating the current editing mode.
+
+k.  New application-settable variable: rl_input_available_hook; function to be
+    called when readline detects there is data available on its input file
+    descriptor.
+
+l.  Readline calls an application-set event hook (rl_event_hook) after it gets
+    a signal while reading input (read returns -1/EINTR but readline does not
+    handle the signal immediately) to allow the application to handle or
+    otherwise note it.
+
+m.  If the user-settable variable `history-size' is set to a value less than
+    0, the history list size is unlimited.
+
+n.  New application-settable variable: rl_signal_event_hook; function that is
+    called when readline is reading terminal input and read(2) is interrupted
+    by a signal.  Currently not called for SIGHUP or SIGTERM.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to readline-6.1 since
+the release of readline-6.0.
+
+New Features in Readline
+
+a.  New bindable function: menu-complete-backward.
+
+b.  In the vi insertion keymap, C-n is now bound to menu-complete by default,
+    and C-p to menu-complete-backward.
+
+c.  When in vi command mode, repeatedly hitting ESC now does nothing, even
+    when ESC introduces a bound key sequence.  This is closer to how
+    historical vi behaves.
+
+d.  New bindable function: skip-csi-sequence.  Can be used as a default to
+    consume key sequences generated by keys like Home and End without having
+    to bind all keys.
+
+e.  New application-settable function: rl_filename_rewrite_hook.  Can be used
+    to rewite or modify filenames read from the file system before they are
+    compared to the word to be completed.
+
+f.  New bindable variable: skip-completed-text, active when completing in the
+    middle of a word.  If enabled, it means that characters in the completion
+    that match characters in the remainder of the word are "skipped" rather
+    than inserted into the line.
+
+g.  The pre-readline-6.0 version of menu completion is available as
+    "old-menu-complete" for users who do not like the readline-6.0 version.
+
+h.  New bindable variable: echo-control-characters.  If enabled, and the
+    tty ECHOCTL bit is set, controls the echoing of characters corresponding
+    to keyboard-generated signals.
+
+i.  New bindable variable: enable-meta-key.  Controls whether or not readline
+    sends the smm/rmm sequences if the terminal indicates it has a meta key
+    that enables eight-bit characters.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to readline-6.0 since
+the release of readline-5.2.
+
+New Features in Readline
+
+a.  A new variable, rl_sort_completion_matches; allows applications to inhibit
+    match list sorting (but beware: some things don't work right if
+    applications do this).
+
+b.  A new variable, rl_completion_invoking_key; allows applications to discover
+    the key that invoked rl_complete or rl_menu_complete.
+
+c.  The functions rl_block_sigint and rl_release_sigint are now public and
+    available to calling applications who want to protect critical sections
+    (like redisplay).
+
+d.  The functions rl_save_state and rl_restore_state are now public and
+    available to calling applications; documented rest of readline's state
+    flag values.
+
+e.  A new user-settable variable, `history-size', allows setting the maximum
+    number of entries in the history list.
+
+f.  There is a new implementation of menu completion, with several improvements
+    over the old; the most notable improvement is a better `completions
+    browsing' mode.
+
+g.  The menu completion code now uses the rl_menu_completion_entry_function
+    variable, allowing applications to provide their own menu completion
+    generators.
+
+h.  There is support for replacing a prefix  of a pathname with a `...' when
+    displaying possible completions.  This is controllable by setting the
+    `completion-prefix-display-length' variable.  Matches with a common prefix
+    longer than this value have the common prefix replaced with `...'.
+
+i.  There is a new `revert-all-at-newline' variable.  If enabled, readline will
+    undo all outstanding changes to all history lines when `accept-line' is
+    executed.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to readline-5.2 since
+the release of readline-5.1.
+
+New Features in Readline
+
+a.  Calling applications can now set the keyboard timeout to 0, allowing
+    poll-like behavior.
+
+b.  The value of SYS_INPUTRC (configurable at compilation time) is now used as
+    the default last-ditch startup file.
+
+c.  The history file reading functions now allow windows-like \r\n line
+    terminators.
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to readline-5.1 since
+the release of readline-5.0.
+
+New Features in Readline
+
+a.  The key sequence sent by the keypad `delete' key is now automatically   
+    bound to delete-char.
+
+b.  A negative argument to menu-complete now cycles backward through the
+    completion list.
+
+c.  A new bindable readline variable:  bind-tty-special-chars.  If non-zero,
+    readline will bind the terminal special characters to their readline
+    equivalents when it's called (on by default).
+
+d.  New bindable command: vi-rubout.  Saves deleted text for possible  
+    reinsertion, as with any vi-mode `text modification' command; `X' is bound
+    to this in vi command mode.
+
+e.  If the rl_completion_query_items is set to a value < 0, readline never
+    asks the user whether or not to view the possible completions.
+
+f.  New application-callable auxiliary function, rl_variable_value, returns
+    a string corresponding to a readline variable's value.
+
+g.  When parsing inputrc files and variable binding commands, the parser
+    strips trailing whitespace from values assigned to boolean variables
+    before checking them.
+
+h.  A new external application-controllable variable that allows the LINES
+    and COLUMNS environment variables to set the window size regardless of
+    what the kernel returns.
+
+
+-------------------------------------------------------------------------------
+This is a terse description of the new features added to readline-5.0 since
+the release of readline-4.3.
+
+New Features in Readline
+
+a.  History expansion has a new `a' modifier equivalent to the `g' modifier
+    for compatibility with the BSD csh.
+
+b.  History expansion has a new `G' modifier equivalent to the BSD csh `g'
+    modifier, which performs a substitution once per word.
+
+c.  All non-incremental search operations may now undo the operation of
+    replacing the current line with the history line.
+
+d.  The text inserted by an `a' command in vi mode can be reinserted with
+    `.'.
+
+e.  New bindable variable, `show-all-if-unmodified'.  If set, the readline
+    completer will list possible completions immediately if there is more
+    than one completion and partial completion cannot be performed.
+
+f.  There is a new application-callable `free_history_entry()' function.
+
+g.  History list entries now contain timestamp information; the history file
+    functions know how to read and write timestamp information associated
+    with each entry.
+
+h.  Four new key binding functions have been added:
+
+	rl_bind_key_if_unbound()
+	rl_bind_key_if_unbound_in_map()
+	rl_bind_keyseq_if_unbound()
+	rl_bind_keyseq_if_unbound_in_map()
+
+i.  New application variable, rl_completion_quote_character, set to any
+    quote character readline finds before it calls the application completion
+    function.
+
+j.  New application variable, rl_completion_suppress_quote, settable by an   
+    application completion function.  If set to non-zero, readline does not
+    attempt to append a closing quote to a completed word.
+    
+k.  New application variable, rl_completion_found_quote, set to a non-zero
+    value if readline determines that the word to be completed is quoted.
+    Set before readline calls any application completion function.
+
+l.  New function hook, rl_completion_word_break_hook, called when readline
+    needs to break a line into words when completion is attempted.  Allows
+    the word break characters to vary based on position in the line.
+
+m.  New bindable command: unix-filename-rubout.  Does the same thing as
+    unix-word-rubout, but adds `/' to the set of word delimiters.
+
+n.  When listing completions, directories have a `/' appended if the
+    `mark-directories' option has been enabled.