changes

android-w.song.android.widget

h.  Posix change to allow `time' as a command by itself to print the elapsed
    user, system, and real times for the shell and its children.

j.  $((...)) is always parsed as an arithmetic expansion first, instead of as
    a potential nested command substitution, as Posix requires.

k.  A new FUNCNEST variable to allow the user to control the maximum shell
    function nesting (recursive execution) level.

l.  The mapfile builtin now supplies a third argument to the callback command:
    the line about to be assigned to the supplied array index.

m.  The printf builtin has a new %(fmt)T specifier, which allows time values
    to use strftime-like formatting.

n.  There is a new `compat41' shell option.

o.  The cd builtin has a new Posix-mandated `-e' option.

p.  Negative subscripts to indexed arrays, previously errors, now are treated
    as offsets from the maximum assigned index + 1.

q.  Negative length specifications in the ${var:offset:length} expansion,
    previously errors, are now treated as offsets from the end of the variable.

r.  Parsing change to allow `time -p --'.

s.  Posix-mode parsing change to not recognize `time' as a keyword if the
    following token begins with a `-'.  This means no more Posix-mode
    `time -p'.  Posix interpretation 267.

t.  There is a new `lastpipe' shell option that runs the last command of a
    pipeline in the current shell context.  The lastpipe option has no
    effect if job control is enabled.

u.  History expansion no longer expands the `$!' variable expansion.

v.  Posix mode shells no longer exit if a variable assignment error occurs
    with an assignment preceding a command that is not a special builtin.

w.  Non-interactive mode shells exit if -u is enabled and an attempt is made
    to use an unset variable with the % or # expansions, the `//', `^', or
    `,' expansions, or the parameter length expansion.

x.  Posix-mode shells use the argument passed to `.' as-is if a $PATH search
    fails, effectively searching the current directory.  Posix-2008 change.

4.  New Features in Readline

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.

b.  New bindable variable `completion-display-width' to set the number of
    columns used when displaying completions.

c.  New bindable variable `completion-case-map' to cause case-insensitive
    completion to treat `-' and `_' as identical.

d.  There are new bindable vi-mode command names to avoid readline's case-
    insensitive matching not allowing them to be bound separately.

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.

------------------------------------------------------------------------------
This document details the changes between this version, bash-4.1-rc,
and the previous version, bash-4.1-beta.

1.  Changes to Bash

a.  Fixed a bug that caused printf to not return a partial value when it
    encountered an error while converting an integer argument.

b.  Fixed a bug that caused setting one of the compatNN options to not
    turn off the others.

c.  The (undocumented) --wordexp option is no longer included by default.

d.  Fixed a bug in conditional command execution that caused it to not
    correctly ignore the exit status under certain circumstances.

e.  Added a configure-time check for correctly-working asprintf/snprintf.

f.  Fixed some problems with line number calculation and display when sourcing
    a file in an interactive shell.

g.  Fixed a bug that caused the shell to crash when using `declare -A foo=bar'.

h.  Fixed a bug that caused an off-by-one error when calculating the directories
    to display with the PROMPT_DIRTRIM option.

2.  Changes to Readline

a.  Fixed a bug that caused applications using the callback interface to not
    react to SIGINT (or other signals) until another character arrived.

------------------------------------------------------------------------------
This document details the changes between this version, bash-4.1-beta,
and the previous version, bash-4.1-alpha.

1.  Changes to Bash

a.  Fixed a bug in mapfile that caused the shell to crash if it was passed the
    name of an associative array.

b.  Fixed a bug that caused the shell to incorrectly split case patterns if
    they contained characters in $IFS.

c.  Fixed a bug that caused the shell to set $? to the wrong value when using
    a construct ending with a variable assignment with set -x enabled and PS4
    containing a command substitution.

d.  Fixed a bug that caused the shell to read commands incorrectly if an
    expansion error occurred under certain conditions in a user-specified
    subshell.

e.  Fixed a bug that caused the shell to set $? incorrectly if a parse error
    occurred in an evaluation context ("eval", trap command, dot script, etc.)

f.  Fixed a bug that caused the shell to attempt command substitution
    completion within a single-quoted string.

g.  Fixed a bug that caused the shell to insert an extra single quote during
    word completion.

h.  Fixed a bug that caused the shell to crash if invoked with the environment
    variable EMACS having a null value.

i.  Fixed a bug that caused bash to incorrectly report the presence of new
    mail in a `maildir' environment.

j.  Fixed a bug that caused the shell to not recognize a here-document ending
    delimiter inside a command substitution.

k.  Fixed a bug that caused the shell to crash when a a dynamic array variable
    was assigned a scalar value.

2.  Changes to Readline

3.  New Features in Bash

a.  The mapfile/readarray builtin no longer stores the commands it invokes via
    callbacks in the history list.

b.  There is a new `compat40' shopt option.

c.  The < and > operators to [[ do string comparisons using the current locale
    only if the compatibility level is greater than 40 (set to 41 by default).

4.  New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-4.1-alpha,
and the previous version, bash-4.0-release.

1.  Changes to Bash

a.  Fixed bugs in the parser involving new parsing of the commands contained
    in command substitution when the substitution is read.

b.  Fixed a bug that caused the shell to dump core when performing programmable
    completion using a shell function.

c.  Fixed a bug in `mapfile' that caused it to invoke callbacks at the wrong
    time.

d.  Fixed a bug that caused the shell to dump core when listing jobs in the
    `exit' builtin.

e.  Fixed several bugs encountered when reading subscripts in associative
    array assignments and expansions.

f.  Fixed a bug that under some circumstances caused an associative array to
    be converted to an indexed array.

g.  Fixed a bug that caused syntax errors and SIGINT interrupts to not set
    $? to a value > 128.

h.  Fixed a bug that caused the shell to remove FIFOs associated with process
    substitution inside shell functions.

i.  Fixed a bug that caused terminal attributes to not be reset when the
    `read' builtin timed out.

j.  Fixed a bug in brace expansion that caused unwanted zero padding of the
    expanded terms.

k.  Fixed a bug that prevented the |& construct from working as intended when
    used with a simple command with additional redirections.

l.  Fixed a bug with the case statment ;& terminator that caused the shell to
    dereference a NULL pointer.

m.  Fixed a bug that caused assignment statements or redirections preceding
    a simple command name to inhibit alias expansion.

n.  Fixed the behavior of `set -u' to conform to the latest Posix interpretation:
    every expansion of an unset variable except $@ and $* will cause the
    shell to exit.

o.  Fixed a bug that caused double-quoted expansions of $* inside word
    expansions like ${x#$*} to not expand properly when $IFS is empty.

p.  Fixed a bug that caused traps to set $LINENO to the wrong value when they
    execute.

q.  Fixed a bug that caused off-by-one errors when computing history lines in
    the `fc' builtin.

r.  Fixed a bug that caused some terminating signals to not exit the shell
    quickly enough, forcing the kernel to send the signal (e.g., SIGSEGV)
    multiple times.

s.  Fixed a bug that caused the shell to attempt to add empty lines to the
    history list when reading here documents.

t.  Made some internal changes that dramatically speeds up sequential indexed
    array access.

u.  Fixed a bug that caused the shell to write past the end of a string when
    completing a double-quoted string ending in a backslash.

v.  Fixed a bug that caused the shell to replace too many characters when a
    pattern match was null in a ${foo//bar} expansion.

w.  Fixed bugs in the expansion of ** that caused duplicate directory names
    and the contents of the current directory to be omitted.

x.  Fixed a bug that caused $? to not be set correctly when referencing an
    unset variable with set -u and set -e enabled.

y.  Fixed a bug caused by executing an external program from the DEBUG trap
    while a pipeline was running.  The effect was to disturb the pipeline
    state, occasionally causing it to hang.

z.  Fixed a bug that caused the ** glob expansion to dump core if it
    encountered an unsearchable directory.

aa. Fixed a bug that caused `command -v' and `command -V' to not honor the
    path set by the -p option.

bb. Fixed a bug that caused brace expansion to take place too soon in some
    compound array assignments.

cc. Fixed a bug that caused programmable completion functions' changes to
    READLINE_POINT to not be reflected back to readline.

dd. Fixed a bug that caused the shell to dump core if a trap was executed
    during a shell assignment statement.

ee. Fixed an off-by-one error when computing the number of positional
    parameters for the ${@:0:n} expansion.

ff. Fixed a problem with setting COMP_CWORD for programmable completion
    functions that could leave it set to -1.

gg. Fixed a bug that caused the ERR trap to be triggered in some cases where
    `set -e' would not have caused the shell to exit.

hh. Fixed a bug that caused changes made by `compopt' to not persist past the
    completion function in which compopt was executed.

ii. Fixed a bug that caused the list of hostname completions to not be cleared
    when HOSTNAME was unset.

jj. Fixed a bug that caused variable expansion in here documents to look in
    any temporary environment.

kk. Bash and readline can now convert file names between precomposed and
    decomposed Unicode on Mac OS X ("keyboard" and file system forms,
    respectively).  This affects filename completion (using new
    rl_filename_rewrite_hook), globbing, and readline redisplay.

ll. The ERR and EXIT traps now see a non-zero value for $? when a parser
    error after set -e has been enabled causes the shell to exit.

mm. Fixed a bug that in brace expansion that caused zero-prefixed terms to
    not contain the correct number of digits.

nn. Fixed a bug that caused the shell to free non-allocated memory when
    unsetting an associative array which had had a value implicitly assigned
    to index "0".

oo. Fixed a memory leak in the ${!prefix@} expansion.

pp. Fixed a bug that caused printf to not correctly report all write errors.

qq. Fixed a bug that caused single and double quotes to act as delimiters
    when splitting a command line into words for programmable completion.

rr. Fixed a bug that caused ** globbing that caused **/path/* to match every
    directory, not just those matching `path'.

ss. Fixed a bug that caused the shell to dump core when running `help' without
    arguments if the terminal width was fewer than 7 characters.

2.  Changes to Readline

a.  The SIGWINCH signal handler now avoids calling the redisplay code if
    one arrives while in the middle of redisplay.

b.  Changes to the timeout code to make sure that timeout values greater
    than one second are handled better.

c.  Fixed a bug in the redisplay code that was triggered by a prompt
    containing invisible characters exactly the width of the screen.

d.  Fixed a bug in the redisplay code encountered when running in horizontal
    scroll mode.

e.  Fixed a bug that prevented menu completion from properly completing
    filenames.

f.  Fixed a redisplay bug caused by a multibyte character causing a line to
    wrap.