#4764: bash-5.1
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Reporter: bdubbs | Owner: lfs-book
Type: task | Status: new
Priority: normal | Milestone: 10.1
Component: Book | Version: SVN
Severity: normal | Keywords:
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New minor version.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
to be more uniform and consistent, which introduces a slight backwards
incompatibility.
o. Fixed a bug with saving the history that resulted in errors not being
propagated to the calling application when the history file is not
writable.
p. Readline only calls chown(2) on a newly-written history file if it
really
needs to, instead of having it be a no-op.
q. Readline now behaves better when operate-and-get-next is used when the
history list is `full': when there are already $HISTSIZE entries.
r. Fixed a bug that could cause vi redo (`.') of a replace command not to
work
correctly in the C or POSIX locale.
s. Fixed a bug with vi-mode digit arguments that caused the last command
to be
set incorrectly. This prevents yank-last-arg from working as intended,
for
example.
3. New Features in Bash
a. `bind -x' now supports different bindings for different editing modes
and
keymaps.
b. Bash attempts to optimize the number of times it forks when executing
commands in subshells and from `bash -c'.
c. Here documents and here strings now use pipes for the expanded document
if
it's smaller than the pipe buffer size, reverting to temporary files if
it's
larger.
d. There are new loadable builtins: mktemp, accept, mkfifo, csv, cut/lcut
e. In posix mode, `trap -p' now displays signals whose disposition is
SIG_DFL
and those that were SIG_IGN when the shell starts.
f. The shell now expands the history number (e.g., in PS1) even if it is
not
currently saving commands to the history list.
g. `read -e' may now be used with arbitrary file descriptors (`read -u
N').
h. The `select' builtin now runs traps if its internal call to the read
builtin
is interrupted by a signal.
i. SRANDOM: a new variable that expands to a 32-bit random number that is
not
produced by an LCRNG, and uses getrandom/getentropy, falling back to
/dev/urandom or arc4random if available. There is a fallback generator
if
none of these are available.
j. shell-transpose-words: a new bindable readline command that uses the
same
definition of word as shell-forward-word, etc.
k. The shell now adds default bindings for shell-forward-word,
shell-backward-word, shell-transpose-words, and shell-kill-word.
l. Bash now allows ARGV0 appearing in the initial shell environment to set
$0.
m. If `unset' is executed without option arguments, bash tries to unset a
shell
function if a name argument cannot be a shell variable name because
it's not
an identifier.
n. The `test -N' operator uses nanosecond timestamp granularity if it's
available.
o. Bash posix mode now treats assignment statements preceding shell
function
definitions the same as in its default mode, since POSIX has changed
and
no longer requires those assignments to persist after the function
returns
(POSIX interp 654).
p. BASH_REMATCH is no longer readonly.
q. wait: has a new -p VARNAME option, which stores the PID returned by
`wait -n'
or `wait' without arguments.
r. Sorting the results of pathname expansion now uses byte-by-byte
comparisons
if two strings collate equally to impose a total order; the result of a
POSIX interpretation (#963 and #1070).
s. Bash now allows SIGINT trap handlers to execute recursively.
t. Bash now saves and restores state around setting and unsetting posix
mode,
instead of having unsetting posix mode set a known state.
u. Process substitution is now available in posix mode.
v. READLINE_MARK: a new variable available while executing commands bound
with
`bind -x', contains the value of the mark.
w. Bash removes SIGCHLD from the set of blocked signals if it's blocked at
shell
startup.
x. `test -v N' can now test whether or not positional parameter N is set.
y. `local' now honors the `-p' option to display all local variables at
the
current context.
z. The `@a' variable transformation now prints attributes for unset array
variables.
aa. The `@A' variable transformation now prints a declare command that
sets a
variable's attributes if the variable has attributes but is unset.
bb. `declare' and `local' now have a -I option that inherits attributes
and
value from a variable with the same name at a previous scope.
cc. When run from a -c command, `jobs' now reports the status of completed
jobs.
dd. New `U', `u', and `L' parameter transformations to convert to
uppercase,
convert first character to uppercase, and convert to lowercase,
respectively.
ee. PROMPT_COMMAND: can now be an array variable, each element of which
can
contain a command to be executed like a string PROMPT_COMMAND
variable.
ff. `ulimit' has a -R option to report and set the RLIMIT_RTTIME resource.
gg. Associative arrays may be assigned using a list of key-value pairs
within
a compound assignment. Compound assignments where the words are not of
the form [key]=value are assumed to be key-value assignments. A
missing or
empty key is an error; a missing value is treated as NULL. Assignments
may
not mix the two forms.
hh. New `K' parameter transformation to display associative arrays as key-
value pairs.
ii. Writing history to syslog now handles messages longer than the syslog
max
length by writing multiple messages with a sequence number.
jj. SECONDS and RANDOM may now be assigned using arithmetic expressions,
since
they are nominally integer variables. LINENO is not an integer
variable.
kk. Bash temporarily suppresses the verbose option when running the DEBUG
trap
while running a command from the `fc' builtin.
ll. `wait -n' now accepts a list of job specifications as arguments and
will
wait for the first one in the list to change state.
mm. The associative array implementation can now dynamically increase the
size of the hash table based on insertion patterns.
nn. HISTFILE is now readonly in a restricted shell.
oo. The bash malloc now returns memory that is 16-byte aligned on 64-bit
systems.
4. New Features in Readline
a. If a second consecutive completion attempt produces matches where the
first
did not, treat it as a new completion attempt and insert a match as
appropriate.
b. Bracketed paste mode works in more places: incremental search strings,
vi
overstrike mode, character search, and reading numeric arguments.
c. Readline automatically switches to horizontal scrolling if the terminal
has
only one line.
d. Unbinding all key sequences bound to a particular readline function now
descends into keymaps for multi-key sequences.
e. rl-clear-display: new bindable command that clears the screen and, if
possible, the scrollback buffer (bound to emacs mode M-C-l by default).
f. New active mark and face feature: when enabled, it will highlight the
text
inserted by a bracketed paste (the `active region') and the text found
by
incremental and non-incremental history searches. This is tied to
bracketed
paste and can be disabled by turning off bracketed paste.
g. Readline sets the mark in several additional commands.
h. Bracketed paste mode is enabled by default.
i. Readline tries to take advantage of the more regular structure of UTF-8
characters to identify the beginning and end of characters when moving
through the line buffer.
j. The bindable operate-and-get-next command (and its default bindings)
are
now part of readline instead of a bash-specific addition.
--
Ticket URL: <http://wiki.linuxfromscratch.org/lfs/ticket/4764>
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