[Pkg-zsh-devel] Bug#1122569: zsh: With RC_EXPAND_PARAM, s:string: does not elide an empty field

[Vincent Lefevre]

Package: zsh
Version: 5.9-8
Severity: normal
Tags: upstream
Forwarded: https://www.zsh.org/mla/workers/2025/msg00816.html

The zshexpn(1) man page says:

  s:string:
[...]
    For historical reasons, the usual behaviour that  empty  array
    elements  are  retained  inside  double quotes is disabled for
    arrays generated by splitting; hence the following:

            line="one::three"
            print -l "${(s.:.)line}"

    produces two lines of output for one and three and elides  the
    empty  field.   To  override  this behaviour, supply the `(@)'
    flag as well, i.e.  "${(@s.:.)line}".

But without the (@) flag, if the RC_EXPAND_PARAM option is set,
this does not elide the empty field:

cventin% line="one::three" ; print -l "${(s.:.)line}"
one
three
cventin% setopt RC_EXPAND_PARAM
cventin% line="one::three" ; print -l "${(s.:.)line}"
one

three
cventin%

-- Package-specific info:

Packages which provide vendor completions:

Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name             Version         Architecture Description
+++-================-===============-============-=======================================================================
ii  bubblewrap       0.11.0-2        amd64        utility for unprivileged chroot and namespace manipulation
ii  curl             8.17.0-3        amd64        command line tool for transferring data with URL syntax
ii  dkms             3.2.2-1         all          Dynamic Kernel Module System (DKMS)
ii  dpkg-dev         1.22.21         all          Debian package development tools
ii  git-buildpackage 0.9.39          all          Suite to help with Debian packages in Git repositories
ii  mercurial-common 7.1.1-1         all          easy-to-use, scalable distributed version control system (common files)
ii  meson            1.10.0-1        all          high-productivity build system
ii  ninja-build      1.13.2-1        amd64        small build system closest in spirit to Make
ii  pass             1.7.4-8         all          lightweight directory-based password manager
ii  pulseaudio-utils 17.0+dfsg1-2+b1 amd64        Command line tools for the PulseAudio sound server
ii  qpdf             12.2.0-1        amd64        tools for transforming and inspecting PDF files
ii  sqv              1.3.0-4         amd64        OpenPGP signature verification program from Sequoia
ii  systemd          258.1-2         amd64        system and service manager
ii  udev             258.1-2         amd64        /dev/ and hotplug management daemon
ii  zathura          0.5.14-3        amd64        document viewer with a minimalistic interface

dpkg-query: no path found matching pattern /usr/share/zsh/vendor-functions/


-- System Information:
Debian Release: forky/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable-debug'), (500, 'proposed-updates-debug'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 6.17.11+deb14-amd64 (SMP w/12 CPU threads; PREEMPT)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages zsh depends on:
ii  debianutils  5.23.2
ii  libc6        2.42-5
ii  libcap2      1:2.75-10+b2
ii  libtinfo6    6.5+20251123-1
ii  zsh-common   5.9-8

Versions of packages zsh recommends:
ii  libgdbm6t64   1.26-1
ii  libncursesw6  6.5+20251123-1
ii  libpcre2-8-0  10.46-1

Versions of packages zsh suggests:
ii  zsh-doc  5.9-8

-- no debconf information

-- 
Vincent Lefèvre <vincent at vinc17.net> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)