952944197f
This fixes three related bugs:
1. Expansions like ${var+set} remained static when used within a
'for', 'while' or 'until' loop; the expansions din't change
along with the state of the variable, so they could not be used
to check whether a variable is set within a loop if the state of
that variable changed in the course of the loop. (BUG_ISSETLOOP)
2. ${IFS+s} always yielded 's', and [[ -v IFS ]] always yielded
true, even if IFS is unset. (BUG_IFSISSET)
3. IFS was incorrectly exempt from '-u' ('-o nounset') checks.
src/cmd/ksh93/sh/macro.c: varsub():
- When getting a node pointer (np) to the parameter to test,
special-case IFS by checking if it has a value and not setting
the pointer if not. The node to IFS always exists, even after
'unset -v IFS', so before this fix it always followed the code
path for a parameter that is set. This fixes BUG_IFSISSET for
${IFS+s} and also fixes set -u (-o nounset) with IFS.
- Before using the 'nv_isnull' macro to check if a regular variable
is set, call nv_optimize() if needed. This fixes BUG_ISSETLOOP.
Idea from Kurtis Rader: https://github.com/att/ast/issues/1090
Of course this only works if SHOPT_OPTIMIZE==1 (the default),
but if not, then this bug is not triggered in the first place.
- Add some comments for future reference.
src/cmd/ksh93/bltins/test.c: test_unop():
- Fix BUG_IFSISSET for [[ -v IFS ]]. The nv_optimize() method
doesn't seem to have any effect here, so the only way that I can
figure out is to special-case IFS, nv_getval()'ing it to check if
IFS has a value in the current scope.
src/cmd/ksh93/tests/variables.sh:
- Add regression tests for checking if a varariable is set within a
loop, within and outside a function with that variable made local
(to check if the scope is honoured). Repeat these tests for a
regular variable and for IFS, for ${foo+set} and [[ -v foo ]].
(cherry picked from commit a2cf79cb98fa3e47eca85d9049d1d831636c9b16)
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| NEWS | ||
| README.md | ||
| TODO | ||
KornShell 93u+m
This repository is used to develop bugfixes to the last stable release (93u+ 2012-08-01) of ksh93, formerly developed by AT&T Software Technology (AST). The sources in this repository were forked from the Github AST repository which is no longer under active development.
To see what's fixed, see NEWS and click on commit messages for full details.
To see what's left to fix, see TODO.
Policy
- No new features. Bug fixes only.
- No major rewrites. No refactoring code that is not fully understood.
- No changes in documented behaviour, except if required for compliance with the POSIX shell language standard which David Korn intended for ksh to follow.
- No 100% bug compatibility. Broken and undocumented behaviour gets fixed.
- No bureaucracy, no formalities. Just fix it, or report it: create issues, send pull requests. Every interested party is invited to contribute.
- To help increase everyone's understanding of this code base, fixes and significant changes should be fully documented in commit messages.
Why?
Between 2017 and 2020 there was an ultimately unsuccessful attempt to breathe new life into the KornShell by extensively refactoring the last unstable AST beta version (93v-). While that ksh2020 branch is now abandoned and still has many critical bugs, it also had a lot of bugs fixed. More importantly, the AST issue tracker now contains a lot of documentation on how to fix those bugs, which makes it possible to backport many of them to the last stable release instead.
In February 2020, having concluded the AST 93v- beta was too broken to base new work on, others decided to start a new fork based on the last stable 93u+ 2012-08-01 release. Unfortunately, as of June 2020, the new ksh-community organisation is yet to see any significant activity four months after its bootstrapping. I hope that will change; I am ready to join efforts with them at any time, as well as anyone else who wants to contribute.
The last stable ksh93 release from 2012 is the least buggy release currently available, but it still has many serious bugs. So it is well past time to start fixing those bugs, leave the rest of the code alone, and get an improved release out there.
Build
After cloning this repo, cd to the top directory of it and run:
./bin/package make
If you have trouble or want to tune the binaries, you may pass additional compiler and linker flags by appending it to the command shown above. E.g.:
./bin/package make \
SHELL=/bin/bash CCFLAGS="-xc99 -D_XPG6 -m64 -xO4" LDFLAGS="-m64"
For more information run
bin/package help
Many other commands in this repo self-document via the --help, --man and
--html options; those that do have no separate manual page.
Test
After compiling, you can run the regression tests. Start by reading the information printed by:
./bin/shtests --man