This document details the changes between this version, bash-5.2-release, and
the previous version, bash-5.2-rc4.

1. Changes to Bash

2. Changes to Readline

a. When replacing a history entry, make sure the existing entry has a non-NULL
   timestamp before copying it; it may have been added by the application, not
   the history library.

3. New Features in Bash

4. New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.2-rc4, and
the previous version, bash-5.2-rc3.

1. Changes to Bash

a. Changed how the compatibility mode enabling of extglob works in conjunction
   with parsing conditional commands.

b. Fixed a problem with aliases containing command substitutions.

2. Changes to Readline

3. New Features in Bash

4. New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.2-rc3, and
the previous version, bash-5.2-rc2.

1. Changes to Bash

a. Added a compatibility mode feature that causes the parser to parse command
   substitutions as if extglob were enabled. If it is enabled before execution,
   parse at execution will succeed. If not, the subsequent execution parse will
   fail.

b. Fixed an issue with handling a `return' executed in a trap action if the
   trap is executed while running in a shell function.

2. Changes to Readline

3. New Features in Bash

4. New Features in Readline

a. Readline now checks for changes to locale settings (LC_ALL/LC_CTYPE/LANG)
   each time it is called, and modifies the appropriate locale-specific display
   and key binding variables when the locale changes.

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.2-rc2, and
the previous version, bash-5.2-rc1.

1. Changes to Bash

a. Fixed a bug that could disable history saving after a compound array
   assignment in an interactive shell.

b. Fixed a bug that could cause incorrect error messages when running a DEBUG
   trap during a conditional or arithmetic command.

c. Fixed a bug that caused test to print an error message when given ! ! arg
   as arguments.

d. Fixed a bug that resulted in incorrect error messages when completing a
   backquoted command substitution.

e. Changed command substitution parsing to reproduce the original text more
   closely when reconsituting the command string from the parsed command.

f. Fixed a bug that could cause an EXIT trap to use the wrong variable context
   when the errexit option is set.

g. Fixed a bug that could cause the parser to incorrectly delimit a token when
   an alias expansion ended with a multibyte character.

2. Changes to Readline

3. New Features in Bash

a. Since there is no `declare -' equivalent of `local -', make sure to use
   `local -' in the output of `local -p'.

b. Null anchored matches in pattern substitution now process `&' in the
   replacement string, like sed.

4. New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.2-rc1, and
the previous version, bash-5.2-beta.

1. Changes to Bash

a. Changes to `wait -p' and how it sets the variable name in the presence of
   valid and invalid PID arguments.

b. Fixed a bug that caused compgen to dump core if the completion engine was
   not initialized.

c. Fixed a memory leak in the variable name programmable completion code.

d. Here-documents and here-strings use tempfiles if the shell compatibility
   level is 50 or lower.

e. Non-interactive shells exit on a syntax error encountered while parsing a
   command substitution.

f. Fixed a bug with inherited parser state while parsing a command substitution.

g. Fixed a bug that caused the shell not to check for terminating signals
   after executing the command_string supplied with `-c' and before executing
   the exit trap.

h. Changes to avoid a make race condition while generating builtins.c.

i. Make it explicit that BASH_REMATCH is always a global variable, and that
   local copies are (currently) ignored.

j. Fixed a bug that caused an ambiguous redirection (>&word) to be printed
   incorrectly (>&word) if no file descriptor was supplied.

2. Changes to Readline

a. Fixed a bug that caused rl_eof_found to be set prematurely while reading a
   multi-character key sequence in callback mode.

3. New Features in Bash

a. In posix mode, the `printf' builtin checks for the `L' length modifier and
   uses long double for floating point conversion specifiers if it's present,
   double otherwise.

b. The `globbing' completion code now takes the `globstar' option into account.

c. `suspend -f' now forces the shell to suspend even if job control is not
   currently enabled.

4. New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.2-beta, and
the previous version, bash-5.2-alpha.

1. Changes to Bash

a. Fixed a problem with command-oriented history and multi-line commands that
   caused embedded blank lines to be run together.

b. Changed the way `&' is quoted when performing pattern substitution and
   `patsub_replacement' is enabled.

c. Fixed some integer overflows when expanding strings or reading the output
   of command substitution larger than 2GB.

d. `wait -p' without the `-n' option now does something useful if there are no
   jobs.

e. Fixed an issue with read timeouts in posix mode.

f. Changed here-document processing to process $'...' and $"..." only when they
   appear in the WORD portion of ${PARAM OP WORD} in the here-document body
   and the body is being expanded.

g. Changed alias expansion in command substitution to be posix-conformant
   (performed while initially parsing the command substitution) when in posix
   mode.

h. Bash optimizes away more forks in subshells.

i. Here-document construction now performs quote removal on the here-document
   delimiter only if it's marked as quoted, which prevents quote characters in
   command substitutions from being removed.

j. Prompt string expansion now gives invisible characters in the expansion of
   the \w, \W, and \s escape sequences a visible representation to avoid
   problems with redisplay.

k. Fixed a problem with SIGINT during the execution of a command bound with
   `bind -x' affecting the saved terminal settings.

l. Fixed an inconsistency with how $@ expands in a construct like ${@:+set}
   or ${array[@]:+set} in the presence of null positional parameters or
   array elements.

2. Changes to Readline

a. Prevent some display problems when running a command as the result of a
   trap or one bound using `bind -x' and the command generates output.

b. Fixed an issue with multi-line prompt strings that have one or more
   invisible characters at the end of a physical line.

c. Fixed an issue that caused a history line's undo list to be cleared when
   it should not have been.

3. New Features in Bash

a. There is a new bindable readline command name: `vi-edit-and-execute-command'.

4. New Features in Readline

a. Two new bindable string variables: active-region-start-color and
   active-region-end-color. The first sets the color used to display the
   active region; the second turns it off. If set, these are used in place
   of terminal standout mode.

b. New readline state (RL_STATE_EOF) and application-visible variable
   (rl_eof_found) to allow applications to detect when readline reads EOF
   before calling the deprep-terminal hook.

c. There is a new configuration option: --with-shared-termcap-library, which
   forces linking the shared readline library with the shared termcap (or
   curses/ncurses/termlib) library so applications don't have to do it.

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.2-alpha, and
the previous version, bash-5.1-release.

1. Changes to Bash

a. Fixed a bug that assigned a value to the variable name supplied as an
   argument to `wait -p' when there were no jobs.

b. Fixed a bug that resulted in performing incorrect word expansion on the
   key/value pairs in a compound array assignment.

c. Fixed a bug that could put the child forked to run a command substitution
   into the wrong process group.

d. Fixed a problem that could cause the lastpipe option to work incorrectly if
   file descriptor 0 was closed.

e. Bash tries to suppress traps if a forked child receives a trapped signal
   before it has a chance to reset its signal handlers.

f. Fixed several memory leaks in compound array assignments.

g. Fixed a problem with performing an assignment with `+=' to an array element
   that was the value of a nameref.

h. Fixed a bug that could cause a nameref containing an array reference using
   `@' or `*' not to expand to multiple words.

i. Fixed a bug where extended glob functions could match `.' or `..' when it
   wasn't explicitly specified, even if dotglob was set.

j. Fixed a bug that caused non-interactive posix-mode shells not to exit on a
   variable assignment error while assigning into the temporary environment.

k. Fixed a bug that caused parsing errors if an alias contained a compound
   array assignment.

l. Fixed a couple of instances where bash checked syntax too aggressively when
   trying to determine how to add a partial command to command-oriented
   history.

m. Fixed a parser problem that caused it not to allow reserved words to follow
   the `((' and `[[' commands.

n. Fixed a bad offset calculation when using negative offsets to `history -d'.

o. Fixed an off-by-one error that caused a read past the end of a buffer when
   reading a multibyte character from the output of a command substitution.

p. Fixed a problem with a failed `exec' command not setting $? to the right
   value for an exit trap.

q. Fixed a problem that caused bash not to unlink FIFOs created as part of
   expanding redirections for an external command.

r. Fixed a bug that could cause aliases not to be expanded in case statements.

s. Fixed a bug that could cause word completion to attempt programmable
   completion for the target of a redirection, instead of filename completion.

t. Fixed a bug that could result in errors after rebinding a key sequence with
   `bind -x' multiple times.

u. Fixed a problem that could result in not quoting the result when performing
   command name completion with a glob pattern in the command name.

v. `mapfile' now uses fully-buffered reads in more cases, which should improve
   bulk read performance.

w. Fixed a bug that caused `wait -n' to not reset its internal state when
   interrupted by a signal, resulting in subsequent calls failing.

x. Fixed a bug with parsing numeric arguments to readline key sequences
   installed with `bind -x'.

y. Bash suppresses forking in several additional cases, including most uses
   of $(<file).

z. If there are multiple `!' tokens in a [[ command, toggle the invert state
   instead of setting it unconditionally.

aa. Fixed a bug where running `fc' on an empty history list would cause the
    shell to crash.

bb. Word completion now checks whether or not a quote character closes a
    quoted string begun on a previous line, so readline doesn't interpret the
    quote as starting a new quoted string.

cc. Fixed a typo that translated \UNNNNNNNN characters that were not valid in
    the current locale encoding as \uNNNNNNNN.

dd. Fixed an issue that could cause bash to print timing statistics for the
    wrong command when `set -e' causes a command to fail.

ee. Bash now runs the exit trap in function context if a failed command in
    the function causes the shell to exit.

ff. Some fixes to how subshells modify $SHLVL.

gg. Fixed a bug that caused `mapfile -t' not to remove the delimiter when the
    delimiter is > 128 in the current encoding.

hh. Fixed a problem that could cause the shell to attempt to free unallocated
    memory if an expansion error occurred.

ii. Fixed a bug in the bash malloc implementation of malloc_usable_size. Bash
    did not use it, but it could cause problems with library functions that
    did.

jj. If the `exec' builtin fails, and the shell does not exit, it restores
    trapped signals to their trapped state.

kk. Fixed a bug that could cause variable assignment arguments to `declare' to
    expand variables using attributes that the call to declare was turning off.

ll. Fixed a bug with LINENO and arithmetic for commands.

mm. Fixed a posix-mode bug that caused tildes not to be expanded after an
    unquoted colon on the right side of an assignment statement.

nn. Fixed a problem with `caller' and line numbers when executing an ERR trap.

oo. Fixed a problem that could make the value returned by ${a:=b} not be the
    final value assigned to a (e.g., if `a' has an attribute that modifies
    the value on assignment).

pp. Fixed a problem with saving multi-line here-documents to the history list
    where the here-document delimiter does not appear on the first line.

qq. Fixed a bug with using += to assign to dynamic variables like RANDOM.

rr. Fixed a bug that caused `set -n' to modify $? if set after execution had
    started.

ss. Builtins like printf/read/wait now behave more consistently when assigning
    arbitrary keys to associative arrays (like `]'. when appropriately quoted).

tt. Fixed a problem with here-document collection printing the wrong prompt
    when parsing a compound list in an interactive shell.

uu. Fixed a problem with quoting shell expansion characters (like `$') when
    they appear in a tab-completed word along with characters that do need
    quoting (e.g.. $HOME/VirtualBox VMs).

2. Changes to Readline

a. Fixed a problem with cleaning up active marks when using callback mode.

b. Fixed a problem with arithmetic comparison operators checking the version.

c. Fixed a problem that could cause readline not to build on systems without
   POSIX signal functions.

d. Fixed a bug that could cause readline to crash if the application removed
   the callback line handler before readline read all typeahead.

e. Added additional checks for read errors in the middle of readline commands.

f. Fixed a redisplay problem that occurred when switching from the digit-
   argument prompt `(arg: N)' back to the regular prompt and the regular
   prompt contained invisible characters.

g. Fixed a problem with restoring the prompt when aborting an incremental
   search.

h. Fix a problem with characters > 128 not being displayed correctly in certain
   single-byte encodings.

i. Fixed a problem with unix-filename-rubout that caused it to delete too much
   when applied to a pathname consisting only of one or more slashes.

j. Fixed a display problem that caused the prompt to be wrapped incorrectly if
   the screen changed dimensions during a call to readline() and the prompt
   became longer than the screen width.

k. Fixed a problem that caused the \r output by turning off bracketed paste
   to overwrite the line if terminal echo was disabled.

l. Fixed a bug that could cause colored-completion-prefix to not display if
   completion-prefix-display-length was set.

m. Fixed a problem with line wrapping prompts when a group of invisible
   characters runs to the right edge of the screen and the prompt extends
   longer then the screen width.

n. Fixed a couple problems that could cause rl_end to be set incorrectly by
   transpose-words.

3. New Features in Bash

a. The bash malloc returns memory that is aligned on 16-byte boundaries.

b. There is a new internal timer framework used for read builtin timeouts.

c. Rewrote the command substitution parsing code to call the parser recursively
   and rebuild the command string from the parsed command. This allows better
   syntax checking and catches errors much earlier. Along with this, if
   command substitution parsing completes with here-documents remaining to be
   read, the shell prints a warning message and reads the here-document bodies
   from the current input stream.

d. The `ulimit' builtin now treats an operand remaining after all of the options
   and arguments are parsed as an argument to the last command specified by
   an option. This is for POSIX compatibility.

e. Here-document parsing now handles $'...' and $"..." quoting when reading the
   here-document body.

f. The `shell-expand-line' and `history-and-alias-expand-line' bindable readline
   commands now understand $'...' and $"..." quoting.

g. There is a new `spell-correct-word' bindable readline command to perform
   spelling correction on the current word.

h. The `unset' builtin now attempts to treat arguments as array subscripts
   without parsing or expanding the subscript, even when `assoc_expand_once'
   is not set.

i. There is a default value for $BASH_LOADABLES_PATH in config-top.h.

j. Associative array assignment and certain instances of referencing (e.g.,
   `test -v') now allow `@' and `*' to be used as keys.

k. Bash attempts to expand indexed and associative array subscripts only
   once when executing shell constructs and word expansions.

l. The `unset' builtin allows a subscript of `@' or `*' to unset a key with
   that value for associative arrays instead of unsetting the entire array
   (which you can still do with `unset arrayname'). For indexed arrays, it
   removes all elements of the array without unsetting it (like `A=()').

m. Additional builtins (printf/test/read/wait) do a better job of not
   parsing array subscripts if array_expand_once is set.

n. New READLINE_ARGUMENT variable set to numeric argument for readline commands
   defined using `bind -x'.

o. The new `varredir_close' shell option causes bash to automatically close
   file descriptors opened with {var}<fn and other styles of varassign
   redirection unless they're arguments to the `exec' builtin.

p. The `$0' special parameter is now set to the name of the script when running
   any (non-interactive) startup files such as $BASH_ENV.

q. The `enable' builtin tries to load a loadable builtin using the default
   search path if `enable name' (without any options) attempts to enable a
   non-existent builtin.

r. The `printf' builtin has a new format specifier: %Q. This acts like %q but
   applies any specified precision to the original unquoted argument, then
   quotes and outputs the result.

s. The new `noexpand_translations' option controls whether or not the translated
   output of $"..." is single-quoted.

t. There is a new parameter transformation operator: @k. This is like @K, but
   expands the result to separate words after word splitting.

u. There is an alternate array implementation, selectable at `configure' time,
   that optimizes access speed over memory use (use the new configure
    --enable-alt-array-implementation option).

v. If an [N]<&WORD- or [N]>&WORD- redirection has WORD expand to the empty
   string, treat the redirection as [N]<&- or [N]>&- and close file descriptor
   N (default 0).

w. Invalid parameter transformation operators are now invalid word expansions,
   and so cause fatal errors in non-interactive shells.

x. New shell option: patsub_replacement. When enabled, a `&' in the replacement
   string of the pattern substitution expansion is replaced by the portion of
   the string that matched the pattern. Backslash will escape the `&' and
   insert a literal `&'.

y. `command -p' no longer looks in the hash table for the specified command.

z. The new `--enable-translatable-strings' option to `configure' allows $"..."
   support to be compiled in or out.

aa. The new `globskipdots' shell option forces pathname expansion never to
    return `.' or `..' unless explicitly matched. It is enabled by default.

bb. Array references using `@' and `*' that are the value of nameref variables
    (declare -n ref='v[@]' ; echo $ref) no longer cause the shell to exit if
    set -u is enabled and the array (v) is unset.

4. New Features in Readline

a. There is now an HS_HISTORY_VERSION containing the version number of the
   history library for applications to use.

b. History expansion better understands multiple history expansions that may
   contain strings that would ordinarily inhibit history expansion (e.g.,
   `abc!$!$').

c. There is a new framework for readline timeouts, including new public
   functions to set timeouts and query how much time is remaining before a
   timeout hits, and a hook function that can trigger when readline times
   out. There is a new state value to indicate a timeout.

d. Automatically bind termcap key sequences for page-up and page-down to
   history-search-backward and history-search-forward, respectively.

e. There is a new `fetch-history' bindable command that retrieves the history
   entry corresponding to its numeric argument. Negative arguments count back
   from the end of the history.

f. `vi-undo' is now a bindable command.

g. There is a new option: `enable-active-region'. This separates control of
   the active region and bracketed-paste. It has the same default value as
   bracketed-paste, and enabling bracketed paste enables the active region.
   Users can now turn off the active region while leaving bracketed paste
   enabled.

h. rl_completer_word_break_characters is now `const char *' like
   rl_basic_word_break_characters.

i. Readline looks in $LS_COLORS for a custom filename extension
   (*.readline-colored-completion-prefix) and uses that as the default color
   for the common prefix displayed when `colored-completion-prefix' is set.

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.1-rc3, and
the previous version, bash-5.1-rc2.

1. Changes to Bash

a. The `assoc_expand_once' option now affects the evaluation of the -v primary
   to test and the [[ compound command.

2. Changes to Readline

a. Fixed a bug that could cause point to be set beyond the end of the line
   buffer when aborting an incremental search.

3. New Features in Bash

4. New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.1-rc2, and
the previous version, bash-5.1-rc1.

1. Changes to Bash

a. Process substitutions started from an interactive shell no longer have their
   standard input implicitly redirected from /dev/null.

b. Fixed an issue with setting the SIGINT trap handler in an interactive shell
   when temporarily running $PROMPT_COMMAND non-interactively.

2. Changes to Readline

a. Terminals that are named "dumb" or unknown do not enable bracketed paste
   by default.

b. Ensure that disabling bracketed paste turns off highlighting the incremental
   search string when the search is successful.

3. New Features in Bash

4. New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.1-rc1, and
the previous version, bash-5.1-beta.

1. Changes to Bash

a. Fixed an inconsistency in the way HISTCMD is calculated when it's expanded
   during a multi-line command.

b. Modified the change to here-document expansion containing backslash-quoted
   double quotes.

c. Fixed a case where the shells's exit status could be greater than 255.

d. Modified changed to process substitution so the executed command has its
   stdin redirected from /dev/null if it was previously interactive and
   reading commands from the terminal.

2. New Features in Bash

a. There is a new contributed loadable builtin: asort.

3. Changes to Readline

a. Fixed a bug that could cause an application with an application-specific
   redisplay function to crash if the line data structures had not been
   initialized.

4. New Features in Readline

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.1-beta, and
the previous version, bash-5.1-alpha.

1. Changes to Bash

a. Fixed a bug that caused name references to variables to not update the
   referenced variable's assignment side effects.

b. Tightened up the parameter transformation error checking for invalid
   transformation operators.

c. System-specific changes for: FreeBSD

d. A few minor changes to move potential uses of stdio functions out of signal
   handling paths.

e. Make sure SIGCHLD is blocked in all cases where waitchld() is not called
   from a signal handler.

f. Changed `command' builtin processing so it no longer starts an extra process
   when run asynchronously (command x &).

g. Avoid performing tilde expansion after `:' in words that look like assignment
   statements when in posix mode.

h. Slight changes to how the `complete' builtin prints out options and actions
   for completion specifications.

i. Several changes to how `local -' restores the values of options and
   $SHELLOPTS.

j. Don't treat a word in a compound assignment as an assignment statement
   unless it has a valid subscript before the `='.

k. Fixed a bug with the DEBUG trap and process substitution that caused the
   terminal's process group to be set incorrectly.

l. Fixed a bug that left readline's signal handlers installed while running a
   shell command from a bindable readline command.

m. Fixed the `fc' builtin to clamp out of range history specifications at the
   boundaries of the history list for POSIX conformance.

n. Fixed a bug that caused ${foo@a} to treat foo as an unset variable if it
   was an array without a value for subscript 0/"0" but had other set
   elements.

o. Fixed a bug that caused the history code to attempt to parse command
   substitutions looking for shell comments before adding them to the history,
   even while parsing here-documents.

p. Fixed a bug that could cause a syntax error in a command read by `eval' to
   exit an interactive shell.

2. New Features in Bash

a. If the hash builtin is listing hashed filenames portably, don't print
   anything if the table is empty.

b. GLOBIGNORE now ignores `.' and `..' as a terminal pathname component.

c. Bash attempts to optimize away forks in the last command in a function body
   under appropriate circumstances.

d. The globbing code now uses fnmatch(3) to check collation elements (if
   available) even in cases without multibyte characters.

e. The `fg' and `bg' builtins now return an error in a command substitution
   when asked to restart a job inherited from the parent shell.

f. The shell now attempts to unlink all FIFOs on exit, whether a consuming
   process has finished with them or not.

3. Changes to Readline

a. Make sure that all undo groups are closed when leaving vi insertion mode.

b. Make sure that the vi-mode `C' and `c' commands enter insert mode even if
   the motion command doesn't have any effect.

c. Fixed several potential memory leaks in the callback mode context handling.

d. If readline is handling a SIGTTOU, make sure SIGTTOU is blocked while
   executing the terminal cleanup code, since it's no longer run in a signal
   handling context.

4. New Features in Readline

a. The signal cleanup code now blocks SIGINT while processing after a SIGINT.

------------------------------------------------------------------------------
This document details the changes between this version, bash-5.1-alpha, and
the previous version, bash-5.0-release.

1. Changes to Bash

a. Fixed a bug that caused a posix-mode shell to not exit if the return builtin
   was executed outside a function or dot script.

b. Fixed a bug where `declare +f' could potentially turn off the function
   attribute.

c. Restored bash-4.4 pathname expansion behavior when a word to be expanded had
   only backslashes, not any of the other globbing characters. This came after
   an extensive POSIX group discussion (interp #1234).

d. There are more changes to avoid performing word expansions multiple times on
   arithmetic expressions.

e. Fixed a bug with alias expansion when the alias ends with a TAB.

f. Fixed a bug that caused programmable completion to return an error if the
   shell function name supplied as an argument to `complete -F' was invalid.

g. There are several fixes to buffer overflows found as the result of fuzzing
   with random input.

h. Fixed a bug that caused the edit-and-execute-command editing command to
   start with the previous history line if invoked on an empty line.

i. Fixed a bug that potentially caused `bind --help' to change readline's
   output stream.

j. Turning off posix mode now restores the vi-insertion mode binding for TAB
   that was in effect when posix mode was enabled.

k. Restore the previous state of job control being enabled if `exec' fails in
   an interactive shell.

l. Fixed a bug that caused the terminal's process group to be set incorrectly
   if job control was turned off before starting an interactive shell.

m. Fixed a bug that caused a crash when HISTSIZE=0.

n. Fixed a word expansion bug that caused null strings on the rhs of expansions
   to be discarded incorrectly.

o. History list management does a better job of handling the situation where
   the number of history entries from the current shell session is greater than
   the number of entries in the history list.

p. Fixed a bug that caused the `fc' builtin to attempt to dereference a newly-
   freed history entry.

q. Fixed a bug that made the `Q' variable transformation not work well with
   `set -u'.

r. There are several word expansion fixes for expanding $* and $@ in contexts
   where word splitting is not going to be performed, since each positional
   parameter must expand to a separate word.

s. Fixed a bug that could cause ^D to exit bash immediately even if there were
   stopped jobs.

t. Fixed a bug with double-quoting and backslash-quoting strings containing
   multibyte characters for reuse.

u. Fixed a bug that caused the line number to be reported incorrectly if the
   shell executed a (command) subshell.

v. Fixed a bug that caused the shell to fail to reap process substitutions
   when they went out of scope, which had unpredictable results.

w. Fixed a bug that caused null strings in arguments to [[ conditional command
   operators to compare incorrectly.

x. Changed the behavior of `wait' without arguments to only wait for background
   processes the current shell instance started, not background children it may
   have inherited.

y. Fixed a bug that could cause command substitution to leave file descriptors
   open if the shell received many SIGINTs.

z. Bash now behaves better if the `**' filename expansion operator encounters a
   symbolic link to a directory, avoiding more cases where it might return
   duplicate pathnames.

aa. Programmable completion now canonicalizes directory names in the same way
    as bash word completion, so `..' is handled consistently.

bb. Fixed a bug when using RETURN as the delimiter to the read builtin; it
    caused readline to set the binding for RETURN incorrectly.

cc. Fixed a bug that caused `history -d' to delay printing an out-of-range
    error message.

dd. Fixed a bug with `bash -c command' where `command' ends with an expanded
    alias.

ee. Fixed a bug that could result in `history -n' adding spurious line feeds to
    commands in the history list.

ff. The $RANDOM random number generator now XORs the top and bottom halves of
    the internal 32-bit value to introduce more randomness. Setting the shell
    compatibility level to 50 or lower undoes this.

gg. Fixed several problems caused by running the DEBUG trap on simple commands
    executed as part of a pipeline.

ii. Fixed a bug that didn't allow `bind -r' to remove the binding for \C-@.

jj. Several fixes to the bash-backward-shellword bindable readline command to
    behave better when at the last character on the line.

kk. If `set -x' is enabled, bash doesn't print a command twice if it's run by
    the `command' builtin.

ll. Fixed a bug with printing function definitions containing here documents.

mm. Fixed a bug that could cause the `bind' builtin to set $? to -1.

nn. Fixed a bug that didn't reset the timezone information correctly when the
    TZ variable was unset.

oo. Fixed several issues with assigning an associative array variable using a
    compound assignment that expands the value of the same variable.

pp. Fixed several places where the shell set $? without setting PIPESTATUS.

qq. Fixed a problem with glob bracket expressions containing invalid character
    classes, collating symbols, or equivalence classes -- they should not
    require a closing right bracket.

rr. Fixed a bug where running a builtin in a subshell did not run the EXIT trap.

ss. Fixed several problems with posix-mode variable assignments preceding
    shell function calls and posix special builtins, so that they create and
    modify variables at the current scope.

tt. Fix history initialization so `bash +o history' works as expected.

uu. Fixed a bug in the bindable edit-and-execute-command command that could
    interfere with the shell's parsing state.

vv. Fixed an issue with nested traps running command substitutions in command
    lines with command substitutions.

ww. Fixed a bug with globbing pathnames that contain invalid multibyte
    characters (sequences that don't correspond to a character in the current
    locale).

xx. Fixed a bug that caused the shell not to exit if a function definition
    failed while errexit was enabled.

yy. Process substitution processes now get their input from /dev/null, since
    they are asynchronous, not interactive, and not jobs.

zz. Setting nocaseglob no longer turns on case-insensitive regexp matching.

aaa. Fixed a bug that resulted in extra blank lines being added to some history
     entries containing here-documents.

bbb. Fixed a bug that resulted in incorrect matching of some patterns in word
     expansion if they expanded to the empty string.

ccc. Fixed here-string expansion so it behaves the same as expansion of the
     rhs of an assignment statement.

ddd. Changed here-document parsing to no longer allow the end of the here
     document to delimit a command substitution.

eee. Several fixes to history expansion: multiple :p modifiers work, a ^ word
     designator works as part of a range, and a `-' is treated as part of a
     search string if it immediately follows a `!'.

fff. Fixed a bug in pattern substitution with null matches in a string
     containing multibyte characters.

ggg. Unbinding a key sequence bound with `bind -x' now removes the key sequence
     from the additional keymap `bind -x' uses.

hhh. Fixed a bug with command start detection for completion so that it doesn't
     mistake brace expansion for the start of a command.

iii. Fixed a bug that caused local variables with the same name as variables
     appearing in a function's temporary environment to not be marked as local.

jjj. Fixed a bug that could cause SIGCHLD to be blocked when executing return
     or exec in the rightmost pipeline element with lastpipe enabled.

kkk. Fixed a bug that could result in commands without the execute bit set
     being added to the command hash table.

lll. Fixed a bug that allowed non-digits to follow the `#' in a `base#number'
     integer constant.

mmm. Fixed a bug that made `time -- command' attempt to execute `--'.

nnn. Fixed a couple of bugs with variable transformation using arrays
     subscripted with `*' or `@'.

ooo. A failure to create a variable using `declare' in a function no longer
     causes the function to return immediately.

ppp. Fixed a bug that could cause the := word expansion to add a non-null
     value if attempting to assign a null string when double-quoted.

qqq. Fixed a bug that could cause backslashes quoting double quotes in here
     document bodies to not be removed when expanding the body.

rrr. Fixed a bug that caused commands following a subshell while the shell is
     reading input from stdin but not interactive, while job control is
     enabled, to be executed twice.

sss. Fixed a bug where receiving SIGTERM from a different process while
     readline was active could cause the shell to terminate.

ttt. In posix mode, running a trap after the read builtin now sees the exit
     status of the read builtin (e.g., 130 after a SIGINT) in $?.

uuu. Fixed a bug with nameref variables referencing array subscripts used in
     arithmetic expressions.

vvv. Fixed a bug that caused the pipeline process group id to be reset in the
     middle of a command list run by a shell started to run a command
     substitution.

www. Restricted shells can no longer read and write history files with pathnames
     containing slashes.

xxx. Fixed a couple of problems with 0 and -0 used as arguments to `fc' when
     not listing commands from the history.

yyy. When `test' is supplied four or more arguments, treat an argument that
     looks like an operator (e.g., -e), but is in a place where only a string
     is valid, as a string, as it would be when using the POSIX rules, instead
     of an operator with a missing argument.

zzz. There is no `compat50' shopt option. Changes to the shell compatibility
     level should use the BASH_COMPAT variable.

aaaa. Redirection failures with compound commands are now treated as errors
      that cause the shell to exit if `errexit' is enabled.

bbbb. Redirection failure error messages no longer expand the word in the
      redirection again.

cccc. History expansion is no longer performed while parsing a here-document
      inside a command substitution.

2. Changes to Readline

a. There are a number of fixes that were found as the result of fuzzing with
   random input.

b. Changed the revert-all-at-newline behavior to make sure to start at the end
   of the history list when doing it, instead of the line where the user hit
   return.

c. When parsing `set' commands from the inputrc file or an application, readline
   now allows trailing whitespace.

d. Fixed a bug that left a file descriptor open to the history file if the
   file size was 0.

e. Fixed a problem with binding key sequences containing meta characters.

f. Fixed a bug that caused the wrong line to be displayed if the user tried to
   move back beyond the beginning of the history list, or forward past the end
   of the history list.

g. If readline catches SIGTSTP, it now sets a hook that allows the calling
   application to handle it if it desires.

h. Fixed a redisplay problem with a prompt string containing embedded newlines.

i. Fixed a problem with completing filenames containing invalid multibyte
   sequences when case-insensitive comparisons are enabled.

j. Fixed a redisplay problem with prompt strings containing invisible multibyte
   characters.

k. Fixed a problem with multibyte characters mapped to editing commands that
   modify the search string in incremental search.

l. Fixed a bug with maintaining the key sequence while resolving a bound
   command in the presence of ambiguous sequences (sequences with a common
   prefix), in most cases while attempting to unbind it.

m. Fixed several buffer overflows found as the result of fuzzing.

n. Reworked backslash handling when translating key sequences for key binding
[--snip--]
