Reproducer from @Saikiran-m:
| ~# sh -c `perl -e 'print "a"x100000'`
| genunix: NOTICE: core_log: sh[1221] core dumped: /var/cores/core.sh.0.1602153496
| Memory fault(coredump)
The crash was in trying to decide whether the name was suitable for
autoloading as a function on $FPATH. This calls strmatch() to check
the name against a regex for valid function name. But the libast
regex code is not designed optimally and uses too much recursion,
limiting the length of the strings it's able to cope with.
src/cmd/ksh93/sh/path.c: path_search():
- Before calling strmatch(), check that the name is shorter than
256 bytes. The maximum length of file names on Linux and macOS is
255 bytes, so an autoload function can't have a name longer than
that anyway.
src/cmd/ksh93/tests/path.sh:
- Add test for this bug.
- Tweak 'command -x' test to not leave a hanging process on Ctrl+C.
Fixes: https://github.com/ksh93/ksh/issues/144
This fixes the following regressions marked TODO in attributes.sh:
$ typeset -L 13 bar; readonly bar; typeset -p bar
typeset -r -L 0 foo # exp.: typeset -r -L 13 foo
$ typeset -R 13 bar; readonly bar; typeset -p bar
typeset -r -R 0 bar # exp.: typeset -r -R 13 bar
$ typeset -Z 13 baz; readonly baz; typeset -p baz
typeset -r -Z 0 -R 0 baz # exp.: typeset -r Z 13 -R 13 baz
I've discovered that these were briefly fixed between fdb9781e (Red
Hat patch for typeset -xu/-xl) and 95fe07d8 (reversal of patch,
different -xu/-xl fix, but reintroduced these regressions).
src/cmd/ksh93/sh/name.c: nv_newattr():
- Replace check from 95fe07d8 with a new one that combines its
approach with that of fdb9781e: do not change size (and hence
return early) if NV_RDONLY and/or NV_EXPORT are the only
attributes that are changing.
src/cmd/ksh93/tests/attributes.sh:
- Enable the TODO regression tests.
This commit corrects how shortint was being applied to various
possible typeset variables in error. The short integer option
modifier 'typeset -s' should only be able to be applied if the
the variable is also an integer. Several issues were resolved
with this fix:
- 'typeset -s': created a short integer having an invalid base
of zero. 'typeset -s foo' created 'typeset -s -i 0 foo=0' and
now will result in an empty string.
- 'typeset -sL': previously resulted in a segmentation fault.
The following are the various incorrect 'typeset' instances
that have been fixed:
$ 'export foo; typeset -s foo; readonly foo; typeset -p foo'
(before) typeset -x -r -s -i 0 foo=0
( after) typeset -x -r foo
$ 'typeset -sL foo=1*2; typeset -p foo'
(before) Segmentation fault (core dumped)
( after) typeset -L 3 foo='1*2'
$ 'typeset -sR foo=1*2; typeset -p foo'
(before) typeset -s -i foo=2
( after) typeset -R 3 foo='1*2'
$ 'typeset -sZ foo=1*2; typeset -p foo'
(before) typeset -F 0 foo=2
( after) typeset -Z 3 -R 3 foo='1*2'
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Add conditional check within the 's' option to only
apply NV_SHORT as well as remove any NV_LONG flag
if NV_INTEGER flag was set.
- Relocate shortint conditional logic to the 'i' option.
src/cmd/ksh93/tests/attributes.sh:
- Adjust regression tests for '-s' and add '-si' check.
This fixes part of https://github.com/ksh93/ksh/issues/87:
Scalar arrays (-a) and associative arrays (-A) of a type created by
'enum' did not consistently block values not specified by the enum
type, yielding corrupted results.
An expansion of type "${array[@]}" yielded random numbers instead
of values for associative arrays of a type created by 'enum'.
This does not yet fix another problem: ${array[@]} does not yield
all values for associative enum arrays.
src/cmd/ksh93/bltins/enum.c: put_enum():
- Always throw an error if the value is not in the list of possible
values for an enum type. Remove incorrect check for the NV_NOFREE
flag. Whatever that was meant to accomplish, I've no idea.
src/cmd/ksh93/sh/array.c: nv_arraysettype():
- Instead of sh_eval()ing a shell assignment, use nv_putval()
directly. Also use the stack (see src/lib/libast/man/stk.3)
instead of malloc to save the value; it's faster and will be
auto-freed at some point. This shortens the function and makes it
faster by not entering into a whole new shell context -- which
also fixes another problem: the error message from put_enum()
didn't cause the shell to exit for indexed enum arrays.
src/cmd/ksh93/sh/name.c: nv_setlist():
- Apply a patch from David Korn that correctly sets the data type
for associative arrays, fixing the ${array[@]} expansion yielding
random numbers. Thanks to @JohnoKing for the pointer.
https://github.com/ksh93/ksh/issues/87#issuecomment-662613887https://www.mail-archive.com/ast-developers@lists.research.att.com/msg00697.html
src/cmd/ksh93/tests/enum.sh:
- Add tests checking that invalid values are correctly blocked for
indexed and associative arrays of an enum type.
Makes progress on: https://github.com/ksh93/ksh/issues/87
Turns out the assumption I was operating on, that Linux and macOS
align arguments on 32 or 64 bit boundaries, is incorrect -- they
just need some extra bytes per argument. So we can use a bit more
of the arguments buffer on these systems than I thought.
src/cmd/ksh93/features/externs:
- Change the feature test to simply detect the # of extra bytes per
argument needed. On *BSD and commercial Unices, ARG_EXTRA_BYTES
shows as zero; on Linux and macOS (64-bit), this yields 8. On
Linux (32-bit), this yields 4.
src/cmd/ksh93/sh/path.c: path_xargs():
- Do not try to calculate alignment, just add ARG_EXTRA_BYTES to
each argument.
- Also add this when substracting the length of environment
variables and leading and trailing static command arguments.
src/cmd/ksh93/tests/path.sh:
- Test command -v/-V with -x.
- Add a robust regression test for command -x.
src/cmd/ksh93/data/builtins.c, src/cmd/ksh93/sh.1:
- Tweak docs. Glob patterns also expand to multiple words.
This test depends on the correctness of the locale data provided
by the OS, and some installations are broken. Failures of this test
most likely do not represent a bug in ksh or libast.
This takes another small step towards disentangling the build
system from the old AT&T environment. The USAGE_LICENSE macros with
author and copyright information, which was formerly generated
dynamically for each file from a database, are eliminated and the
copyright/author information is instead inserted into the AST
getopt usage strings directly.
Repetitive license/copyright information is also removed from the
getopt strings in the builtin commands (src/lib/libcmd/*.c and
src/cmd/ksh93/data/builtins.c). There's no need to include 55
identical license/copyright strings in the ksh binary; one (in the
main ksh getopt string, shown by ksh --man) ought to be enough!
This makes the ksh binary about 10k smaller.
It does mean that something like 'enum --author', 'typeset
--license' or 'shift --copyright' will now not show those notices
for those builtins, but I doubt anyone will care.
It is not correct to save sh.ifstable (a.k.a. shp->ifstable) before
calling a function and then restore it after; this can cause field
splitting to malfunction. See 70368c57.
The change to init.c in the Red Hat patch applied in 18b3f4aa
(shp->ifstable[0] = S_EOF) appears to be sufficient.
src/cmd/ksh93/bltins/alarm.c:
- Revert save/restore of sh.ifstable.
src/cmd/ksh93/tests/builtins.sh:
- Tweak the regression test to work correctly on a slower machine,
i.e. a Raspberry Pi running FreeBSD 12.2 arm64 (thanks to hyenias
for providing testing access).
This commit resolves the following incorrect variable assignments:
$ unset a; typeset -uF a=2; typeset -p a
typeset -X a=0x1.0000000000p+1
$ unset a; typeset -Fu a=2; typeset -p a
typeset -X a=0x1.0000000000p+1
$ unset a; typeset -ulF a=2; typeset -p a
typeset -l -X a=0x1.0000000000p+1
$ unset a; typeset -Ful a=2; typeset -p a
typeset -l -X a=0x1.0000000000p+1
$ unset a; typeset -Eu a=2; typeset -p a
typeset -E -X a=2
$ unset a; typeset -Eul a=2; typeset -p a
typeset -l -E -X a=2
src/cmd/ksh93/bltins/typeset.c:
- If the unsigned option (-u) was provided in conjunction with a
floating point (-F) then due to a flag collision with NV_UNSIGN
and NV_HEXFLOAT both having the value of NV_LTOU caused the
floating point to become a hexadecimal floating point (-X) in
error. Also, if a -E option flag was followed with a -u option
then the resulting variable would be both a scientific notation
and a hexadecimal floating point at the same time.
src/cmd/ksh93/tests/attributes.sh:
- Add regression tests.
Co-authored-by: Martijn Dekker <martijn@inlv.org>
An unquoted variable expansion evaluated in a DEBUG trap action
caused IFS field splitting to be deactivated in code executed after
the trap action. Thanks to Koichi Nakashima for the reproducer:
| v=''
| trap ': $v' DEBUG
| A="a b c"
| set -- $A
| printf '%s\n' "$@"
|
| Expected
|
| a
| b
| c
|
| Actual
|
| a b c
src/cmd/ksh93/sh/fault.c: sh_trap():
- Remove incorrect save/restore of sh.ifstable, the internal state
table for field splitting. This reverts three lines added in ksh
93t+ 2009-11-30. Analysis: As an expansion is split into fields
(macro.c, lines 2367-2471), sh.ifstable is modified. If that
happens within a DEBUG trap, any modifications in ifstable are
undone by the restoring memccpy, leaving an inconsistent state.
src/cmd/ksh93/COMPATIBILITY:
- Document the DEBUG trap fixes, particularly the incorrect
inheritance by subshells and functions that some scripts may now
rely on because this bug is so longstanding. (re: 2a835a2d)
src/cmd/ksh93/tests/basic.sh:
- Add relevant tests.
Resolves: https://github.com/ksh93/ksh/issues/155
TODO: add a -T (-o functrace) option as in bash, which should allow
subshells and ksh-style functions to inherit DEBUG traps.
P.S.: The very handy multishell repo allows us to use 'git blame'
to trace the origin of the recently fixed DEBUG trap bugs.
The off-by-one error causing various bugs, reverted in 2a835a2d,
was introduced in ksh 93t 2008-07-25:
8e947ccf
(fault.c, line 321)
The incorrect check causing the exit status bug, reverted in
d00b4b39, was introduced in ksh 93t 2008-11-04:
b1ade268
(fault.c, line 459)
The ifstable save/restore causing the field splitting bug, reverted
in this commit, was introduced in ksh 93t+ 2009-11-30:
53d9f009
(fault.c, lines 440, 444, 482)
So all the bugs reported in #155 were fixed by simply reverting
these specific changes. I think that they are some experiments that
the developers simply forgot to remove. I've suspected such a thing
multiple times before. ksh93 was developed by researchers who were
genius innovators, but incredibly sloppy maintainers.
Turns out the previous commit also fixed the bug that disables the
DEBUG trap if a redirection is used in a DEBUG trap action -- in
other words, that's the same bug.
src/cmd/ksh93/tests/basic.sh:
- Add test from the reproducer in the bug report.
Makes progress on: https://github.com/ksh93/ksh/issues/155
This trap failed to be restored correctly when being trapped in
a subshell, causing corruption or a crash when restoring the
parent shell environment's trap upon leaving the subshell.
Thanks to Koichi Nakashima for the report and reproducer.
src/cmd/ksh93/sh/fault.c: sh_sigreset():
- Fix an off-by-one error in the loop that restores the
pseudosignal traps.
src/cmd/ksh93/tests/basic.sh:
- Test overwriting the main shell trap in a subshell for all
pseudosignals.
Makes progress on: https://github.com/ksh93/ksh/issues/155
UnixWare's ps prefers to read psinfo (from the proc structure in
kernel memory) within /proc as an anti-Trojan horse measure.
Updates to argv[0] are still reflected within /proc/$pid/cmdline,
which is useful for diagnostic purposes.
src/cmd/ksh93/sh/main.c:
- Remove __USLC__ from the list of platforms excluded from the
fixargs method.
src/cmd/ksh93/tests/basic.sh:
- Read /proc/$pid/cmdline instead of ps on UnixWare.
What is this for? See cefe087d
src/cmd/ksh93/Mamfile:
- Make iffe generate a test for the presence of setproctitle(3).
src/cmd/ksh93/sh/main.c:
- Include setproctitle test result.
- Re-enable fixargs() for FreeBSD and DragonFly BSD.
Disable it for UnixWare.
- fixargs(): Add _lib_setproctitle version. Keep it simple with a
128-character buffer array -- should be plenty for 'ps' output.
- fixargs(): Fix an off-by-one in zeroing the rest of the buffer.
src/cmd/ksh93/tests/basic.sh:
- Update the relevant regression test to run on FreeBSD/DragonFly
and tolerate the "ksh: " prefix added by setproctitle(3).
This adds informative error messages if incompatible options are
given. It also documents the exclusive -m, -n and -T options on
separate usage lines, as was already done with -f. The usage
message for incompatible options now looks something like this:
| $ ksh -c 'typeset -L10 -F -f -i foo'
| ksh: typeset: -i/-F/-E/-X cannot be used with -L/-R/-Z
| ksh: typeset: -f cannot be used with other options
| Usage: typeset [-bflmnprstuxACHS] [-a[type]] [-i[base]] [-E[n]]
| [-F[n]] [-L[n]] [-M[mapping]] [-R[n]] [-X[n]]
| [-h string] [-T[tname]] [-Z[n]] [name[=value]...]
| Or: typeset -f [name...]
| Or: typeset -m [name=name...]
| Or: typeset -n [name=name...]
| Or: typeset -T [tname[=(type definition)]...]
| Help: typeset [ --help | --man ] 2>&1
(see also the previous commit, e21a053e)
Unfortunately the first "Usage" line has some redundancies with the
"Or:" lines showing separate usages. It doesn't seem to be possible
to avoid this; it's a flaw in how libast generates everything
(usage, help, manual) from one huge getopt(3) string. I still think
the three added "Or:" lines are an improvement as it wasn't
previously shown that these options need to be used on their own.
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Instead of only showing a generic usage message, add an
informative error message if incompatible options were given.
- Conflicting options detection was failing because NV_LJUST and
NV_EXPNOTE have the same bitmask value. Use a new 'isadjust'
flag for -L/-R/-Z to remember if one of these was set.
- Detect conflict between -L/-R/-Z and a float option, not just -i.
src/cmd/ksh93/include/name.h, src/cmd/ksh93/data/msg.c:
- Add the two new error messages for incompatible options.
src/cmd/ksh93/data/builtins.c: sh_opttypeset[]:
- Add a space after 'float' in in "[+float?\btypeset -lE\b]" as
this makes 'float' appear on its own line, improving formatting.
- Show -m, -n, -T on separate usage lines like -f, as none of these
can be combined with other options.
- Remove "cannot be combined with other options" from -m and -n
descriptions, as that should now be clear from the separate usage
lines -- and even if not, the error message is now informative.
src/cmd/ksh93/sh.1, src/cmd/ksh93/COMPATIBILITY:
- Update.
src/cmd/ksh93/tests/types.sh:
- Remove obsolete test: 'typeset -RF' is no longer accepted.
(It crashed in 93u+, so this is not an incompatibility...)
Resolves: https://github.com/ksh93/ksh/issues/48
For example, this changes 'typeset -Q' (a bad option) from:
| ksh: typeset: -Q: unknown option
| Usage: typeset [-bflmnprstuxACHS] [-a[type]] [-i[base]] [-E[n]]
| [-F[n]] [-L[n]] [-M[mapping]] [-R[n]] [-X[n]]
| [-h string] [-T[tname]] [-Z[n]] [name[=value]...]
| Or: typeset [ options ] -f [name...]
to:
| ksh: typeset: -Q: unknown option
| Usage: typeset [-bflmnprstuxACHS] [-a[type]] [-i[base]] [-E[n]]
| [-F[n]] [-L[n]] [-M[mapping]] [-R[n]] [-X[n]]
| [-h string] [-T[tname]] [-Z[n]] [name[=value]...]
| Or: typeset -f [name...]
| Help: typeset [ --help | --man ] 2>&1
src/lib/libast/misc/optget.c: args():
- Revert the changes done in 6916a873 and ae92cd89. The --help and
--man labels weren't added consistently (they did not show up in
the example above) whereas they did show up unnecessarily in the
manual page itself.
- In the usage section and usage messges, only show an [ options ]
label on the first usage line; don't redundantly repeat on second
and further ("Or:") lines.
- In usage and --help (but not --man), add a new "Help:" line
telling the user about the --help and --man options. This
replaces the reverted changes. Show the 2>&1 redirection as a
reminder that you need to do this to pipe it into a pager, as
everything is written to standard error!
- Add some comments clarifying what I think this code does...
src/cmd/ksh93/tests/builtins.sh:
- Update to match changes in getopts usage output.
This fixes the following:
trap ':' DEBUG
r=$(exit 123)
echo $? # Expected 123, but actually 0.
Thanks to Koichi Nakashima for the report and reproducer.
src/cmd/ksh93/sh/fault.c: sh_trap():
- Restore the saved current exit status (exitval) for all traps.
Do not except the DEBUG trap from doing that. I've no idea why
this exception was made, but it's not correct.
src/cmd/ksh93/tests/basic.sh:
- Add tests.
Makes progress on: https://github.com/ksh93/ksh/issues/155
Commit d1483150 did not fully fix#153.
Test case from Harald van Dijk that was still failing:
$ mkdir test
$ cd test
$ rmdir $PWD
$ mkdir $PWD
$ ksh -c "(cd /); pwd"
/
Forking a virtual subshell in that case is needed to avoid ending
up in a directory that replaced the PWD, because it will not be
possible for a process to change back to the original directory.
src/cmd/ksh93/bltins/cd_pwd.c:
- When deciding whether to fork, instead of attempting to opendir
the PWD, compare the inodes $PWD and "." to determine if $PWD
still actually refers to the current directory. This uses the
test_inode() function which is also used by 'test foo -ef bar'.
src/cmd/ksh93/tests/subshell.sh:
- Add test based on the above.
Progresses: https://github.com/ksh93/ksh/issues/153
src/cmd/ksh93/tests/variables.sh:
- Fork the subshell with the test that includes unsetting LINENO
and changing its type. Otherwise, some side effect of that leaks
out of the subshell, messing up $LINENO. This is a bug, but it's
low priority -- we may get to it someday. Marked with a TODO.
- Do the LC_* tests in their own subshell. Skip them if changing
LANG to an invalid value does not produce a diagnostic message.
This occurs on OpenBSD and Alpine Linux (with musl libc). It
looks like their C libraries do not verify the locale, so
failures here are not a ksh problem; skip the tests in that case.
This commit also further mitigates the problems with restoring an
inaccessible or nonexistent PWD on exiting a virtual subshell.
Harald van Dijk writes:
> On a build of ksh with -fsanitize=undefined to help diagnose
> problems:
>
> $ mkdir deleted
> $ cd deleted
> $ rmdir ../deleted
> $ ksh -c '(cd /; (cd /)); :'
> /home/harald/ksh/src/cmd/ksh93/sh/subshell.c:561:22: runtime
> error: null pointer passed as argument 1, which is declared to
> never be null
> Segmentation fault (core dumped)
>
> Note that it segfaults the same with default compilation flags,
> but it does not print out the useful extra message. The code
> assumes that pwd is non-null and passes it to strcmp without
> checking, but it will be null if the current directory cannot be
> determined, for instance because it has been deleted.
src/cmd/ksh93/sh/subshell.c: sh_subshell():
- Avoid the null pointer dereference reported above.
src/cmd/ksh93/bltins/cd_pwd.c: b_cd():
- Fork a virtual subshell even on systems with fchdir(2) if the
present working directory tests as inaccessible on invoking 'cd';
it may no longer exist and fchdir would fail to get a handle.
(For the test we have to opendir(3) the full path to the PWD and
not ".", as the latter may succeed even if the PWD is gone.)
src/cmd/ksh93/data/builtins.c:
- Update 'cd' version string.
Fixes: https://github.com/ksh93/ksh/issues/153
Related: https://github.com/ksh93/ksh/issues/141
This now makes ksh build on DragonFly BSD.
bin/package, src/cmd/INIT/package.sh:
- DragonFly also needs the -lm hack for LDFLAGS.
src/cmd/ksh93/sh/main.c, src/cmd/ksh93/tests/basic.sh:
- fixargs() doesn't work on DragonFly either
(re: 9b7c392a, 159fb9ee, cefe087d).
The following are backported from:
https://github.com/att/ast/issues/26#issuecomment-313927854https://github.com/att/ast/pull/19
src/lib/libast/comp/setlocale.c:
- Add missing #include <errno.h> since errno is used.
src/lib/libast/features/standards:
- Do not set any standards macros (_POSIX_SOURCE etc) on FreeBSD or
DragonflyBSD; they disable too much functionality on those.
src/lib/libast/features/wchar:
- Set _STDFILE_DECLARED on DragonFly, too.
src/lib/libast/include/sfio.h, src/lib/libast/include/sfio_t.h,
src/lib/libast/sfio/_sfopen.c, src/lib/libast/sfio/sfclrlock.c,
src/lib/libast/sfio/sfhdr.h, src/lib/libast/sfio/sfnew.c,
src/lib/libast/sfio/sfset.c:
- Rename SF_* macros to SFIO_* to avoid a conflict with system
headers.
src/lib/libast/string/strexpr.c:
- Rename error() to err() to avoid a conflict.
~- and ~+ are ksh93-specific tilde expansions that expand to
$OLDPWD and $PWD, respectively. On some systems, $OLDPWD is not set
on entry to the test script, because it is not exported to the
environment. This made it unset before any 'cd' was executed,
which (correctly) disabled ~- expansion.
src/cmd/ksh93/tests/basic.sh:
- Before testing 'cd ~-', make sure $OLDPWD is set by cd'ing to
/dev first (a directory guaranteed by POSIX).
src/cmd/ksh93/sh/main.c: fixargs():
- Erase the entire length of the command arguments buffer (the
space from argv[0] until environ[0]) so that remnants of longer
command arguments aren't left in 'ps' output when executing a
hashbang-ess script with a shorter command line.
- Disable fixargs() on FreeBSD. It has never had any effect on that
system; apparently it either requires another method to rewrite
arguments for 'ps' output purposes (which?) or it's not possible.
src/cmd/ksh93/tests/basic.sh:
- Skip the test if running on FreeBSD.
ksh 93u+ has a subshell leak bug where a variable exported in
function in a subshell is also visible in a different subshell.
This is long fixed in 93u+m, but there wasn't a regression test for
this particular bug yet, so this commit adds one.
This pulls a new version of sh_iosafefd() from:
https://github.com/oracle/solaris-userland/blob/master/components/ksh93/patches/285-30771135.patch
It was written by Kurtis Rader for ksh2020:
https://github.com/att/ast/issues/198https://github.com/att/ast/pull/199
It is presumably better than the Red Hat version and also comes
with more regression test cases (although it still doesn't fix
modernish BUG_CSUBSTDO, which remains in the TODO file).
This commit does not go along with other peripheral changes from
that patch, i.e. a different name and location of this function.
src/cmd/ksh93/sh/io.c:
- Replace sh_iosafefd() as above.
src/cmd/ksh93/tests/subshell.sh:
- Add and tweak tests from the patch.
This change is pulled from here:
https://github.com/oracle/solaris-userland/blob/master/components/ksh93/patches/280-23332860.patch
Info and reproducers:
https://github.com/att/ast/issues/36
In a -c script (like ksh -c 'commands'), the last command
misredirects standard output if an EXIT or ERR trap is set.
This appears to be a side effect of the optimisation that
runs the last command without forking.
This applies a patch by George Lijo that flags these specific
cases and disables the optimisation.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/bltins/trap.c,
src/cmd/ksh93/sh/init.c,
src/cmd/ksh93/sh/main.c,
src/cmd/ksh93/sh/xec.c:
- Apply patch as above.
src/cmd/ksh93/tests/io.sh:
- Add the reproducers from the bug report as regression tests.
The forking fix implemented in 102868f8 and 9d428f8f, which stops
the main shell's hash table from being cleared if PATH is changed
in a subshell, can cause a significant performance penalty for
certain scripts that do something like
( PATH=... command foo )
in a subshell, especially if done repeatedly. This is because the
hash table is cleared (and hence a subshell forks) even for
temporary PATH assignments preceding commands.
It also just plain doesn't work. For instance:
$ hash -r; (ls) >/dev/null; hash
ls=/bin/ls
Simply running an external command in a subshell caches the path in
the hash table that is shared with a main shell. To remedy this, we
would have to fork the subshell before forking any external
command. And that would be an unacceptable performance regression.
Virtual subshells do not need to fork when changing PATH if they
get their own hash tables. This commit adds these. The code for
alias subshell trees (which was removed in ec888867 because they
were broken and unneeded) provided the beginning of a template for
their implementation.
src/cmd/ksh93/sh/subshell.c:
- struct subshell: Add strack pointer to subshell hash table.
- Add sh_subtracktree(): return pointer to subshell hash table.
- sh_subfuntree(): Refactor a bit for legibility.
- sh_subshell(): Add code for cleaning up subshell hash table.
src/cmd/ksh93/sh/name.c:
- nv_putval(): Remove code to fork a subshell upon resetting PATH.
- nv_rehash(): When in a subshell, invalidate a hash table entry
for a subshell by creating the subshell scope if needed, then
giving that entry the NV_NOALIAS attribute to invalidate it.
src/cmd/ksh93/sh/path.c: path_search():
- To set a tracked alias/hash table entry, use sh_subtracktree()
and pass the HASH_NOSCOPE flag to nv_search() so that any new
entries are added to the current subshell table (if any) and do
not influence any parent scopes.
src/cmd/ksh93/bltins/typeset.c: b_alias():
- b_alias(): For hash table entries, use sh_subtracktree() instead
of forking a subshell. Keep forking for normal aliases.
- setall(): To set a tracked alias/hash table entry, pass the
HASH_NOSCOPE flag to nv_search() so that any new entries are
added to the current subshell table (if any) and do not influence
any parent scopes.
src/cmd/ksh93/sh/init.c: put_restricted():
- Update code for clearing the hash table (when changing $PATH) to
use sh_subtracktree().
src/cmd/ksh93/bltins/cd_pwd.c:
- When invalidating path name bindings to relative paths, use the
subshell hash tree if applicable by calling sh_subtracktree().
- rehash(): Call nv_rehash() instead of _nv_unset()ting the hash
table entry; this is needed to work correctly in subshells.
src/cmd/ksh93/tests/leaks.sh:
- Add leak tests for various PATH-related operations in the main
shell and in a virtual subshell.
- Several pre-existing memory leaks are exposed by the new tests
(I've confirmed these in 93u+). The tests are disabled and marked
TODO for now, as these bugs have not yet been fixed.
src/cmd/ksh93/tests/subshell.sh:
- Update.
Resolves: https://github.com/ksh93/ksh/issues/66
@stephane-chazelas writes:
> Per POSIX[*], cd should skip the $CDPATH processing if the first
> component of the directory given to cd is . or ...
>
> Yet, with ksh93u+m 2021-01-03 at least, while that's OK with ..,
> it's not with . with or without the posix option:
>
> $ CDPATH=/ ./ksh -o posix -c 'cd -P ./etc && pwd'
> /etc
> /etc
>
> It seems to be a regression introduced with ksh93u+ as I can't
> reproduce it with ksh93u or any version prior to that. I can also
> reproduce in u+, v- and the ksh2020 from the Ubuntu 20.04
> package.
src/cmd/ksh93/bltins/cd_pwd.c: b_cd():
- Skip $CDPATH processing not only if the path is absolute, but
also if the initial path component is '.' or '..' (in the latter
case the $CDPATH processing was done but appeared to be a no-op).
src/cmd/ksh93/tests/builtins.sh:
- Add regression test.
[*] https://pubs.opengroup.org/onlinepubs/9699919799.2018edition/utilities/cd.html
Fixes: https://github.com/ksh93/ksh/issues/151
A recent change in Github's Ubuntu test runners exposed a problem
in the way the all_paths test function replicates 'whence -a'
functionality, causing spurious regression test failures.
The problem occurs when e.g. /bin is a symlink to /usr/bin, but
both are in $PATH. The all_paths function treats them as separate
but 'whence -a' detects a duplicate and will not output /usr/bin/*.
I have not succeeded in making all_paths match 'whence -a' exactly.
src/cmd/ksh93/tests/path.sh: function all_paths:
- Using the -ef test expression operator, remove entries from $PATH
that point to the same directory as another entry in $PATH (e.g.
when /bin is a symlink to /usr/bin but both are in $PATH).
Avoiding such dupes works around the problem.
GMT and UTC have identical time but are used in different contexts.
When the system time zone is set to GMT (e.g. in the UK at winter
time), the 'printf %T' test could fail as it correctly uses GMT
whereas the test expects UTC.
src/cmd/ksh93/tests/builtins.sh:
- Fix possible false negative in 'printf %T\\n now' test by
replacing GMT with UTC in both 'date' output and 'printf %T'
output, instead of only the former.
Issuing typeset floating point numerics having a precision of 0
failed as the precision/size was being overwritten with the string
length of the value, e.g. 'typeset -F0 x=5.67' would result in
'typeset -F 4 x=5.6700' as len('5.67') is 4.
src/cmd/ksh93/include/nval.h:
- Created a symbolic name of NV_FLTSIZEZERO to respresent a float
having a precision/size of 0. NV_FLTSIZEZERO needs to be a
negative value.
src/cmd/ksh93/bltins/typeset.c:
- In b_typeset(), added code to set tdata.argnum to NV_FLTSIZEZERO
for E, F, X options.
- In setall(), adjusted code to allow for tp->argnum to be negative.
src/cmd/ksh93/sh/name.c: nv_newattr():
- Adjusted option value only change code to handle NV_FLTSIZEZERO as
well as changed to directly setting np->nvsize instead of using
nv_setsize(np,size) as nv_setsize might contain conflicting and/or
redundant code.
- Added missing conditional check of '!(newatts&NV_INTEGER)' to
constrain the size==0 code block to justified strings as
NV_LJUST, NV_RJUST, or NV_ZFILL are only valid for strings if
NV_INTEGER is not set. This code block was mistakenly setting
the precision/size value to the length of the value of an
assignment for floats whereas it should only be performing
auto assignment length for justified strings.
src/cmd/ksh93/tests/builtins.sh:
- Remove redundant extra bincat=$(whence -p cat).
- Move whence -v/-a tests to path.sh.
- Fix 'whence -q' test so errors are counted outside of a subshell.
src/cmd/ksh93/tests/path.sh:
- Add all_paths function that is basically a reimplementation of
'whence -a -p' in shell. Useful for testing 'whence'.
- Move whence -v/-a tests to here, changing them to use all_paths
where needed. Also fix the 'whence -a' function autoloading
regression test to do the same. This fixes the tests for systems
(such as Slackware) where commands such as 'ls' or 'chmod' have
more than one path in even the default $PATH.
src/cmd/ksh93/bltins/typeset.c: b_typeset():
- For integer bases change argnum check to default values that
are < 2 or > 64 to 10 instead of allowing invalid base values
that ksh cannot process.
src/cmd/ksh93/bltins/typeset.c: setall():
- Remove argnum check for integer base of 1 as base cannot be 1.
- Relocate strlen(name) to inside of conditional check for
np->nvfun as this code does not need to run all.
- Remove no-op oldname code
src/cmd/ksh93/tests/attributes.sh:
- Add typeset -i base bounds checks to default base 10
src/cmd/ksh93/tests/builtins.sh:
- Fix a test so it doesn't fail if 'whence -a' finds multiple paths
for 'ls'.
src/cmd/ksh93/tests/coprocess.sh
- Update known failure comment with current information.
Autoloading a function caused the calling script's $LINENO to be
off by the number of lines in the function definition file. In
addition, while running autoloaded functions, errors/warnings were
reported with wrong line numbers.
src/cmd/ksh93/sh/path.c:
- Save $LINENO (shp->inlineno) before autoloading a function, reset
it to 1 so that the correct line number offset is remembered for
the function definition, and restore it after.
src/cmd/ksh93/tests/variables.sh:
- Add regression test for $LINENO, directly and in error messages,
within and outside a non-autoloaded and an autoloaded function.
Fixes: https://github.com/ksh93/ksh/issues/116
ksh 93u+ introduced a regression in the combination of the
'set -o pipefail' and 'set -e'/'set -o errexit' options:
$ ksh93 -o errexit -o pipefail -c \
'(exit 3) | true; echo "still here despite $? status"'
still here despite 3 status
The bug is in how the the huge sh_exec() function in xec.c handles
the 'echeck' flag. Near the end of sh_exec(), this flag triggers a
sh_chktrap() call to check whether to trigger any traps, including
the ERR trap -- and that same function also handles the errexit
option, which is basically the same as 'trap "exit" ERR'.
We can learn more easily how sh_exec() works by inserting debug
warnings in all its 'switch(type&COMMSK)' cases, like:
case TCOM:
errormsg(SH_DICT,ERROR_warn(0),"[DEBUG] TCOM");
... and same for all the others. With that done, the output
of a very simple dummy pipeline looks as follows:
$ arch/*/bin/ksh -c 'true | true | true'
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TFIL
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TFORK
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TFORK
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TSETIO
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TCOM
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TCOM
arch/darwin.i386-64/bin/ksh: warning: [DEBUG] TCOM
So, it looks like sh_exec() handles this pipeline as follows:
TFIL
|_____TFORK
| |_____TCOM
|_____TFORK
| |_____TCOM
|_____TSETIO
|_____TCOM
Each time a pipeline like command1 | command2 | ... is executed,
sh_exec() is invoked with type TFIL; this then recursively invokes
sh_exec() to handle the individual elements. The last element of
the pipe triggers a sh_exec() run with type TSETIO; since it is run
in the current shell environment, it is effectively treated as a
command with an input redirection. All the previous elements are of
type TFORK instead, because they are executed asynchronously in
separate, forked subshell processes. Finally, the TFORK or TSETIO
code then recursively calls sh_exec() again with type TCOM to
actually execute the commands.
When reading the code, we find that the 'echeck' flag is set as
part of the TSETIO code. This makes sense of why only an error in
the last element of the pipe triggers the errexit/ERR trap action.
So that's the bug: the flag is set in the wrong place.
This can be fixed by setting that flag in the TFIL handling code
instead, as this is what calls everything else and collects all the
exit statuses. So the sh_chktrap() call is now executed after
handling the entire pipeline, at the TFIL recursion level.
This also allows getting rid of the special-casing in the buggy
TSETIO version. The SH_ERREXIT state is restored at the end of each
sh_exec() call, so since we're now doing this at a lower recursion
level, it will already have been restored.
src/cmd/ksh93/sh/xec.c: sh_exec():
- Fix the bug as per the above.
src/cmd/ksh93/tests/options.sh:
- Add tests for errexit and ERR trap combined with pipefail.
src/cmd/ksh93/tests/basic.sh:
- Tweak a couple of tests that reported a trap wasn't triggered
even if it was actually triggered more than once.
Fixes: https://github.com/ksh93/ksh/issues/121
Thanks to Stéphane Chazelas for the bug report.
'typeset -xu' and 'typeset -xl' would export the variable but fail
to change case in the value under certain conditions.
Original patch:
642af4d6/f/ksh-20120801-xufix.patch
This applies the patch essentially without change and adds a
regression test based on the reproducer provided in the RH bug.
Unfortunately there is no description of how the patch works and
it's a little obscure to me. As far as I can figure out, the cause
of the problem was that nv_newattr() erroneously processed a
nonexistent size option-argument such as what can be given to
options like typeset -F, e.g. typeset -F3 for 3 digits after the
dot. A nonexistent size argument is represented by the value of -1.
