-This document details the changes between this version, bash-4.3-rc1, and the
-previous version, bash-4.3-beta2.
+This document details the changes between this version, bash-4.4-alpha, and
+the previous version, bash-4.3-release.
+
+1. Changes to Bash
+
+a. A bug that caused pipelines to be corrupted while running the DEBUG trap
+ was fixed.
+
+b. A bug that accidentally omitted the `-R' unary operator from `test' was
+ fixed.
+
+c. A bug that could cause the shell to not restore the terminal's process
+ group on shell exit was fixed.
+
+d. Several changes were made to programmable completion to accommodate
+ assumptions made by the bash-completion package.
+
+e. Bash no longer inhibits C-style escape processing ($'...') while performing
+ pattern substitution word expansions.
+
+f. Fixed a bug that caused `return' executed from a trap handler to use the
+ wrong return status when one was not supplied as an argument.
+
+g. In Posix mode, defining a function with the same name as a special
+ builtin is now an error, fatal only when the shell is not interactive.
+
+h. Fixed a bug that caused compound array assignments to discard unset or null
+ variables used as subscripts, thereby making it appear as if the index was
+ not present.
+
+i. Fixed a bug that caused extended glob patterns to incorrectly match
+ filenames with a leading `.'.
+
+j. Fixed a bug involving sign extension when reallocating the input line
+ after a history expansion, causing segmentation faults.
+
+k. Bash now does a better job at identifying syntax errors during word
+ completion and tailoring completion appropriately.
+
+l. Bash now uses the current locale's decimal point in comamnd timing output.
+
+m. Fixed a bug that caused segmentation faults while reading here documents if
+ PS2 contains a command substitution.
+
+n. There are several changes to how $@ is expanded when unquoted but in a
+ context where word splitting is not performed (e.g., on the rhs of an
+ assignment or in a conditional command).
+
+o. Bash now quotes command hash table entries that contain shell metacharacters
+ when displaying hash table contents.
+
+p. Fixed a potential file descriptor leak when dup2() fails while performing a
+ redirection.
+
+q. Fixed a bug that caused directory names evaluated during word completion to
+ be dequoted twice.
+
+r. Fixed several bugs which could result in indirect variable expansion and
+ namerefs creating variables with invalid names or referencing variables
+ set to the empty string.
+
+s. Fixed a bug that caused bash to not expand $0 in word expansions where it
+ should.
+
+t. Fixed a bug that caused bash to perform process substitution if <(
+ appeared inside an arithmetic context.
+
+u. Fixed a bug in extglob pattern parsing that caused slashes in the pattern
+ to be confused as directory names.
+
+v. Fixed several bugs with treatment of invisible variables (variables with
+ attributes that are unset because they have never been assigned values).
+
+w. Fixed a bug that caused the `read' builtin to not clean up readline's
+ state when using the -e and -t options together and the read timed out.
+
+x. Fixed a bug that caused the shell to exit with the wrong (but non-zero)
+ value if a command was not found or was not executable.
+
+y. Fixed a bug that caused the `time' reserved word to not be recognized as
+ such in all contexts where it should have been.
+
+z. Fixed a bug that caused the shell to close process subsitution file
+ descriptors when executing a script without the `#!' leading line.
+
+aa. Fixed a typo that caused the `compat42' shell option to set the wrong
+ compatibility level.
+
+bb. The shell now handles process substitution commands with embedded
+ parentheses the same way as it does when parsing command substitution.
+
+cc. Fixed a bug that caused nested pipelines and the `lastpipe' shell option
+ to produce core dumps.
+
+dd. Fixed a bug that caused patterns containing `*' to match pathnames in cases
+ where slashes must be matched explicitly.
+
+ee. Fixed a problem with patterns containing `:' in colon-separated variables
+ lik GLOBIGNORE.
+
+ff. Fixed a bug that caused indirect variable expansion using indexed arrays to
+ always use index 0.
+
+gg. Fixed a parsing problem that caused quoted newlines immediately following a
+ command substitution to be mishandled in certain cases.
+
+hh. Fixed a potential buffer overflow on systems without locale_charset or the
+ bash replacement.
+
+ii. Fixed a bug that caused background processes to modify the terminal's
+ process group under certain circumstances.
+
+jj. Asynchronous commands now always set $? to 0 and are not affected by
+ whether or not the command's exit status is being inverted.
+
+kk. Fixed a problem that caused a line ending with an escaped newline and
+ containingh a prior `eval' to be incorrectly parsed.
+
+ll. Fixed an issue with programmable completion and `!' in extglob patterns
+ used as arguments to `compgen -X'.
+
+mm. Word completion now treats the two-character token `>|' as requiring
+ filename expansion.
+
+nn. Bash no longer expands tildes in $PATH elements while in Posix mode.
+
+oo. Fixed a bug that caused bash to not clean up readline's state, including
+ the terminal settings, if it received a fatal signal while in a readline()
+ call (including `read -e' and `read -s').
+
+pp. Fixed bug that caused importing shell functions from the environment to
+ execute additional commands following the function.
+
+qq. Fixed a bug that caused the parser to return a lookahead character pushed
+ back by a previous call, even when on another line.
+
+rr. Fixed a bug that caused many here-documents or many nested case statements
+ to overflow an internal stack.
+
+ss. Changed the way bash encodes exported functions for inclusion in the
+ environment to avoid name collisions with valid variable names and to
+ indicate that they are exported functions.
+
+tt. Fixed a bug that could result in an invalid memory access when processing
+ a here document delimited by end of file or end of string.
+
+uu. Fixed a bug that could cause an invalid memory access if a command was run
+ before initializing the job control framework.
+
+vv. When in Posix mode, bash prints shell function definitions as Posix
+ specifies them, without the leading `function' keyword.
+
+ww. The variable attribute display builtins no longer display variables with
+ invalid names that were imported from the environment.
+
+xx. Fixed a bug that could allow `break' or `continue' executed from shell
+ functions to affect loops running outside of the function.
+
+yy. Fixed a bug that could cause a restricted shell to attempt to import shell
+ functions from the environment.
+
+zz. The shell now allows double-quoted identifiers in arithmetic expressions.
+
+aaa. Fixed a bug that could allow scalar variables subscripted using [@] in
+ word expansions to be incorrectly quoted.
+
+bbb. The shell now makes sure to ignore SIGTSTP/SIGTTIN/SIGTTOU in child
+ processes if they were ignored at shell startup, even if job control is
+ in effect.
+
+ccc. Fixed a bug that could cause $* to be split on spaces when IFS is set to
+ the empty string.
+
+ddd. Posix says that expanding $* in a pattern context where the expansion is
+ double-quoted should not treat $* as if it were double quoted.
+
+eee. Bash now restores getopts' internal state between calls to getopts even if
+ a shell function declares a local copy of OPTIND.
+
+fff. Fixed a bug that could cause `history -r' or `history -n' to read identical
+ lines from the history file more than once.
+
+ggg. The commands executed by `bind -x' now redisplay at most the final line
+ of a multi-line prompt, and those commands may return 124 to indicate that
+ the entire prompt should be redrawn.
+
+hhh. Fixed a bug that could cause `mapfile' to create variables with invalid
+ names.
+
+iii. The shell only goes into debugging mode when --debugger is supplied if
+ the debugger initialization file is present.
+
+jjj. Fixed a bug that disallowed an assignment to (implicit) subscript 0 of an
+ existing array in a declare command that set the readonly attribute.
+
+kkk. Fixed a bug that inadvertently allowed assignments to FUNCNAME to disable
+ its special status.
+
+lll. Appending to an existing array variable using the compound assignment
+ syntax (var+=(aaa)) should not affect assignments to existing subscripts
+ appearing in the compound assignment.
+
+mmm. Fixed a bug that could cause the shell to crash when a variable with a
+ null value was passed in the temporary environment and the variable's
+ attributes are modified using `declare' while performing a redirection.
+
+nnn. Fixed a bug in printf so that a missing precision specifier after a `.'
+ is treated as 0.
+
+ooo. Fixed a bug that attempted to use the internal command timing to time
+ pipeline components if the pipeline elements are separated by newlines.
+
+ppp. Fixed a bug that caused `declare -al foo=(ONE TWO THREE)' to not lowercase
+ the values on assignment.
+
+qqq. Bash does a better job of determining whether or not files are executable
+ when running on Windows, since the X_OK flag to access(2) is not supported.
+
+rrr. Fixed a bug that caused some of the shell's internal traps (e.g., ERR) to
+ be interrupted (and leave incorrect state) by pending SIGINTs.
+
+sss. Fixed a bug in the bash interface to history expansion to avoid attempting
+ expansion if the history expansion character occurs in a command
+ substitution.
+
+ttt. Fixed a bug that caused the select command to crash if the REPLY variable
+ ends up empty (e.g., if it's made readonly)
+
+uuu. Bash handles backslash-quoting of multibyte characters better when quoting
+ output that is intended to be reused.
+
+vvv. System-specific changes for: Windows, Cygwin.
+
+www. Fixes for upper and lower-casing multibyte characters, some locales have
+ characters whose upper and lowercase versions have different numbers of
+ bytes.
+
+xxx. Fixed a bug that caused the ERR trap in a shell function to have the
+ right value for $LINENO.
+
+yyy. Fixed a bug that resulted in incorrect quoting of regexps for the =~
+ operator when an open brace appears without a close brace.
+
+zzz. Fixed a bug in the array unset operation that caused it to attempt to
+ parse embedded single and double quotes.
+
+aaaa. Fixed a bug that caused $* to not expand with the first character of
+ $IFS as a separator in a context where word splitting will not take
+ place.
+
+bbbb. Fixed two bugs that could cause the shell to dereference a null pointer
+ while attempting to print an error message from arithmetic expansion.
+
+cccc. Fixed a bug that resulted in short-circuited evaluation when reading
+ commands from a string ending in an unquoted backslash, or when sourcing
+ a file that ends with an unquoted backslash.
+
+dddd. Fixed a bug that resulted in the no-fork optimization not cleaning up
+ any FIFOs created by process substitution.
+
+eeee. If the -T option is not set, allow the source builtin and shell functions
+ to set a DEBUG trap that persists after the sourced file or function
+ returns, instead of restoring the old (unset) value unconditionally.
+
+ffff. Fixed a bug that caused redirections to not be undone on some syntax
+ errors, e.g., when parsing a command substitution.
+
+gggg. Bash only adds asynchronous commands to the table of background pids
+ whose status it remembers, to avoid it growing too large during scripts
+ that create and reap large numbers of child processes. This means that
+ `wait' no longer works on synchronous jobs, but $? can be used to get
+ the exit status in those cases.
+
+hhhh. Bash now checks whether or not a shell script argument is a directory
+ before trying to open it; Posix says implementations may allow open(2)
+ on a directory.
+
+iiii. Fixed a bug that could cause the shell to set the terminal's process
+ group to a background process group when running as part of a pipeline.
+
+jjjj. Made a few changes to strings to avoid possible potential negative effects
+ caused by malicious translations.
+
+kkkk. Fixed a bug that caused the `unset' builtin to continue to treat its
+ arguments as functions after unsetting a function when invoked with no
+ options.
+
+llll. Fixed a bug that would not replace empty strings using pattern
+ substitution even if the pattern matched the empty string.
+
+mmmm. Fixed a bug with word completion that prevented some characters from
+ being backslash-quoted (backquote, dollar sign).
+
+nnnn. Fixed a bug that prevented a command from the history re-executed by the
+ `fc' builtin from setting verbose mode.
+
+oooo. Fixed a bug that caused the shell to not enable and disable function
+ tracing with changes to the `extdebug' shell option.
+
+pppp. Fixed a bug that caused assignments to nameref variables pointing to
+ unset variables with attributes but no values to create variables with
+ incorrect names.
+
+qqqq. Fixed a bug that caused `unset' on nameref variables (without -n) to
+ unset the wrong variable under certain circumstances.
+
+rrrr. Fixed a bug that caused close braces occurring in brace expansions within
+ command substitutions to incorrectly terminate parameter expansions.
+
+ssss. Fixed a bug that caused `command -p' to temporarily alter $PATH.
+
+tttt. Fixed a bug that caused interactive shells compiled without job control
+ to return incorrect status values for child processes when running a
+ single command that creates enough children to use the entire PID space.
+
+uuuu. `esac' should not be recognized as a reserved word when it appears as the
+ second or later pattern in a case statement pattern list.
+
+vvvv. Fixed a bug that caused the completion code to read past the end of the
+ readline line buffer while skipping assignment statements to find the
+ command name.
+
+2. Changes to Readline
+
+a. A bug that caused vi-mode `.' to be unable to redo `c', `d', and `y'
+ commands with modifiers was fixed.
+
+b. Fixed a bug that caused callback mode to dump core when reading a
+ multiple-key sequence (e.g., arrow keys).
+
+c. Fixed a bug that caused the redisplay code to erase some of the line when
+ using horizontal scrolling with incremental search.
+
+d. Readline's input handler now performs signal processing if read(2) is
+ interrupted by SIGALRM or SIGVTALRM.
+
+e. Fixed a problem with revert-all-at-newline freeing freed memory.
+
+f. Clarified the documentation for the history_quotes_inhibit_expansion
+ variable to note that it inhibits scanning for the history comment
+ character and that it only affects double-quoted strings.
+
+g. Fixed an off-by-one error in the prompt printed when performing searches.
+
+h. Use pselect(2), if available, to wait for input before calling read(2), so
+ a SIGWINCH can interrupt it, since it doesn't interrupt read(2).
+
+i. Some memory leaks caused by signals interrupting filename completion have
+ been fixed.
+
+j. Reading EOF twice on a non-empty line causes EOF to be returned, rather
+ than the partial line. This can cause partial lines to be executed on
+ SIGHUP, for example.
+
+k. Fixed a bug concerning deleting multibyte characters from the search
+ string while performing an incremental search.
+
+l. Fixed a bug with tilde expanding directory names in filename completion.
+
+m. Fixed a bug that did not allow binding sequences beginning with a `\'.
+
+n. Fixed a redisplay bug involving incorrect line wrapping when the prompt
+ contains a multibyte character in the last screen column.
+
+o. Fixed a bug that caused history expansion to disregard characters that are
+ documented to delimit a history event specifier without requiring `:'.
+
+p. Fixed a bug that could cause reading past the end of a string when reading
+ the value when binding the set of isearch terminators.
+
+q. Fixed a bug that caused readline commands that depend on knowing which
+ key invoked them to misbehave when dispatching key sequences that are
+ prefixes of other key bindings.
+
+r. Paren matching now works in vi insert mode.
+
+3. New Features in Bash
+
+a. There is now a settable configuration #define that will cause the shell
+ to exit if the shell is running setuid without the -p option and setuid
+ to the real uid fails.
+
+b. Command and process substitutions now turn off the `-v' option when
+ executing, as other shells seem to do.
+
+c. The default value for the `checkhash' shell option may now be set at
+ compile time with a #define.
+
+d. The `mapfile' builtin now has a -d option to use an arbitrary character
+ as the record delimiter, and a -t option to strip the delimiter as
+ supplied with -d.
+
+e. The maximum number of nested recursive calls to `eval' is now settable in
+ config-top.h; the default is no limit.
+
+f. The `-p' option to declare and similar builtins will display attributes for
+ named variables even when those variables have not been assigned values
+ (which are technically unset).
+
+g. The maximum number of nested recursive calls to `source' is now settable
+ in config-top.h; the default is no limit.
+
+h. All builtin commands recognize the `--help' option and print a usage
+ summary.
+
+i. Bash does not allow function names containing `/' and `=' to be exported.
+
+j. The `ulimit' builtin has new -k (kqueues) and -P (pseudoterminals) options.
+
+k. The shell now allows `time ; othercommand' to time null commands.
+
+l. There is a new `--enable-function-import' configuration option to allow
+ importing shell functions from the environment; import is enabled by
+ default.
+
+m. `printf -v var ""' will now set `var' to the empty string, as if `var=""'
+ had been executed.
+
+n. GLOBIGNORE, the pattern substitution word expansion, and programmable
+ completion match filtering now honor the value of the `nocasematch' option.
+
+o. There is a new ${parameter@spec} family of operators to transform the
+ value of `parameter'.
+
+p. Bash no longer attempts to perform compound assignment if a variable on the
+ rhs of an assignment statement argument to `declare' has the form of a
+ compound assignment (e.g., w='(word)' ; declare foo=$w); compound
+ assignments are accepted if the variable was already declared as an array,
+ but with a warning.
+
+q. The declare builtin no longer displays array variables using the compound
+ assignment syntax with quotes; that will generate warnings when re-used as
+ input, and isn't necessary.
+
+r. Executing the rhs of && and || will no longer cause the shell to fork if
+ it's not necessary.
+
+s. The `local' builtin takes a new argument: `-', which will cause it to save
+ and the single-letter shell options and restore their previous values at
+ function return.
+
+t. `complete' and `compgen' have a new `-o nosort' option, which forces
+ readline to not sort the completion matches.
+
+u. Bash now allows waiting for the most recent process substitution, since it
+ appears as $!.
+
+v. The `unset' builtin now unsets a scalar variable if it is subscripted with
+ a `0', analogous to the ${var[0]} expansion.
+
+w. `set -i' is no longer valid, as in other shells.
+
+x. BASH_SUBSHELL is now updated for process substitution and group commands
+ in pipelines, and is available with the same value when running any exit
+ trap.
+
+y. Bash now checks $INSIDE_EMACS as well as $EMACS when deciding whether or
+ not bash is being run in a GNU Emacs shell window.
+
+z. Bash now treats SIGINT received when running a non-builtin command in a
+ loop the way it has traditionally treated running a builtin command:
+ running any trap handler and breaking out of the loop.
+
+aa. New variable: EXECIGNORE; a colon-separate list of patterns that will
+ cause matching filenames to be ignored when searching for commands.
+
+bb. Aliases whose value ends in a shell metacharacter now expand in a way to
+ allow them to be `pasted' to the next token, which can potentially change
+ the meaning of a command (e.g., turning `&' into `&&').
+
+4. New Features in Readline
+
+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.
+
+b. There is a new bindable variable, `enable-bracketed-paste', which enables
+ support for a terminal's bracketed paste mode.
+
+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.
+
+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 document details the changes between this version, bash-4.3-release, and
+the previous version, bash-4.3-rc2.
+
+1. Changes to Bash
+
+a. Only Posix-mode shells should exit on an assignment failure in the
+ temporary environment preceding a special builtin. This is how it's been
+ documented.
+
+b. Fixed a bug that caused a failed special builtin to not exit a posix-mode
+ shell if the failing builtin was on the LHS of a && or ||.
+
+c. Changed the handling of unquoted backslashes in regular expressions to be
+ closer to bash-4.2.
+
+d. globstar (**) no longer traverses symbolic links that resolve to
+ directories. This eliminates some duplicate entries.
+
+e. Fixed a bug that caused a SIGCHLD trap handler to not be able to change the
+ SIGCHLD disposition.
+
+f. Fixed a bug that caused a crash when -x was enabled and a command
+ contained a printable multibyte (wide) character.
+
+g. Fixed a bug that caused an interactive shell without line editing enabled
+ to read invalid data after receiving a SIGINT.
+
+h. Fixed a bug that caused command word completion to fail if the directory in
+ $PATH where the completion would be found contained single or double quotes.
+
+i. Fixed a bug that caused a shell with -v enabled to print commands in $()
+ multiple times.
+
+2. Changes to Readline
+
+a. Fixed a bug that caused `undo' to reference freed memory or null pointers.
+
+3. New Features in Bash
+
+a. The [[ -v ]] option now understands array references (foo[1]) and returns
+ success if the referenced element has a value.
+
+------------------------------------------------------------------------------
+This document details the changes between this version, bash-4.3-rc2, and the
+previous version, bash-4.3-rc1.
1. Changes to Bash
k. Displaying a nameref variable with `declare -p' now displays the nameref
variable and its value rather than following the nameref chain.
+l. Fixed a problem with interrupt handling that caused a second and subsequent
+ SIGINT to be ignored by interactive shells.
+
+m. Fixed a bug that caused certain positional parameter and array expansions
+ to mishandle (discard) null positional parameters and array elements.
+
+n. The shell no longer blocks receipt of signals while running trap handlers
+ for those signals, and allows most trap handlers to be run recursively
+ (running trap handlers while a trap handler is executing).
+
+o. The shell now handles backslashes in regular expression arguments to the
+ [[ command's =~ operator slightly differently, resulting in more
+ consistent behavior.
+
2. Changes to Readline
a. Fixed a bug that could cause readline to crash and seg fault attempting to
4. New Features in Readline
+a. When creating shared libraries on Mac OS X, the pathname written into the
+ library (install_name) no longer includes the minor version number.
------------------------------------------------------------------------------
This document details the changes between this version, bash-4.3-rc1, and the
previous version, bash-4.3-beta2.
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.
+ called when readline needs to check whether there is data available on its
+ input source. The default hook checks rl_instream.
l. Readline calls an application-set event hook (rl_signal_event_hook) after
it gets a signal while reading input (read returns -1/EINTR but readline
projects / thirdparty / bash.git / blobdiff