* Add xfail tests to show how :||= matchers should behave in order to
provide completion features that cannot be implemented with :|=
matchers.
* Update compwid.yo to further describe the correct behavior.
* Update compwid.yo to use completion terminology more consistently.
If the file was sourced from an interactive shell with
INTERACTIVE_COMMENTS not set, comments were not parsed.
Note there is a remaining edge case where the sourced
file is in fact entered at the comment line.
Changes typeset such that ${newparam-notset} yields "notset" and
"typeset -p newparam" does not show an assignment to the parameter. This
is similar to the default behavior of bash and ksh, with minor differences
in typeset output.
Also add tests for some POSIX incompatibilities plus minor changes for test
harness robustness.
zsh typically runs the final command in a pipeline in the main shell
instead of a subshell. However, POSIX specifies that all commands in a
pipeline run in a subshell, but permits zsh's behavior as an extension.
The default /bin/sh implementations on various Linux distros and the
BSDs always use a subshell for all components of a pipeline.
Since zsh may be used as /bin/sh in some cases (such as macOS Catalina),
it makes sense to have the common sh behavior when emulating sh, so do
that by checking for being the final item of a multi-item pipeline and
creating a subshell in that case.
From the comment above execpline(), we know the following:
last1 is a flag that this command is the last command in a shell that
is about to exit, so we can exec instead of forking. It gets passed
all the way down to execcmd() which actually makes the decision. A 0
is always passed if the command is not the last in the pipeline. […]
If last1 is zero but the command is at the end of a pipeline, we pass
2 down to execcmd().
So there are three cases to consider in this code:
• last1 is 0, which means we are not at the end of a pipeline, in which
case we should not change behavior.
• last1 is 1, which means we are effectively running in a subshell,
because nothing that happens due to the exec is going to affect the
actual shell, since it will have been replaced. So there is nothing
to do here.
• last1 is 2, which means our command is at the end of the pipeline, so
in sh mode we should create a subshell by forking.
input is nonzero if the input to this process is a pipe that we've
opened. At the end of a multi-stage pipeline, it will necessarily be
nonzero.
Note that several of the tests may appear bizarre, since most developers
do not place useless variable assignments directly at the end of a
pipeline. However, as the function tests demonstrate, there are cases
where assignments may occur when a shell function is used at the end of
a command. The remaining assignment tests simply test additional cases,
such as the use of local, that would otherwise be untested.
Oliver Kiddle
Daniel Shahaf
Dimitris Apostolou
Marlon Richert
Marlon Richert
Bart Schaefer
Peter Stephenson
Jun-ichi Takimoto
Peter Stephenson
dana
brian m. carlson
Mikael Magnusson
Joshua Krusell