Package: dash
Version: 0.5.11+git20210120+802ebd4-1
Tags: patch
At present, /bin/sh is always diverted. The diversion takes one of three
forms:
A. diverted by package dash, pointing to dash
B. diverted by package bash (but performed by dash.postinst), pointing
to bash
C. local diversion
The local diversion gives freedom to administrators to manually point
their /bin/sh at bash and seems to be still in use. dash.postinst takes
care not to mess with such diversions and that should continue to work.
Unless there is a local diversion, dash.postinst sets up either A or B
depending on a debconf question defaulting to A. Since /bin/sh normally
points to dash when not diverted, the diversion A seems unnecessary. B
will have to continue to exist for as long as dash supports changing
/bin/sh via debconf.
Diversion A was not always unnecessary. It was added with reason.
/bin/sh was formerly owned by bash and this path was transferred from
bash to dash. Now if bash was upgraded before dash, /bin/sh could go
missing. To prevent that situation, both packages added a diversion.
This upgrade sequence has long since been completed in some ancient
stable release. Therefore, the need for diversion A no longer exists. It
can be removed now. I'm attaching a patch to implement that. It removes
any existing diversion of dash on upgrade and only creates diversions
when retargeting /bin/sh at bash. The vast majority of default
installations will go without a diversion and without /bin/sh.distrib.
Please consider applying it.
Helmut
diff --minimal -Nru dash-0.5.11+git20210120+802ebd4/debian/changelog
dash-0.5.11+git20210120+802ebd4/debian/changelog
--- dash-0.5.11+git20210120+802ebd4/debian/changelog 2021-03-04
10:22:32.000000000 +0100
+++ dash-0.5.11+git20210120+802ebd4/debian/changelog 2021-06-03
20:19:40.000000000 +0200
@@ -1,3 +1,10 @@
+dash (0.5.11+git20210120+802ebd4-1.1) UNRELEASED; urgency=medium
+
+ * Non-maintainer upload.
+ * Remove unnecessary diversion in case /bin/sh points to dash. (Closes: #-1)
+
+ -- Helmut Grohne <hel...@subdivi.de> Thu, 03 Jun 2021 20:19:40 +0200
+
dash (0.5.11+git20210120+802ebd4-1) unstable; urgency=medium
* New upstream snapshot.
diff --minimal -Nru dash-0.5.11+git20210120+802ebd4/debian/dash.postinst
dash-0.5.11+git20210120+802ebd4/debian/dash.postinst
--- dash-0.5.11+git20210120+802ebd4/debian/dash.postinst 2021-03-04
10:22:32.000000000 +0100
+++ dash-0.5.11+git20210120+802ebd4/debian/dash.postinst 2021-06-03
20:19:40.000000000 +0200
@@ -25,7 +25,7 @@
diverter=$(dpkg-divert --listpackage $dfile)
truename=$(dpkg-divert --truename $dfile)
- if [ "$diverter" = dash ]; then
+ if [ -z "$diverter" ]; then
# good.
return
fi
@@ -35,7 +35,7 @@
return
fi
- if [ -n "$diverter" ] && [ "$diverter" != bash ]; then
+ if [ "$diverter" != bash ]; then
# Let dpkg-divert error out; we are not taking
# over the diversion, unless we added it
# ourselves on behalf of bash.
@@ -45,7 +45,6 @@
fi
dpkg-divert --package bash --no-rename --remove $dfile
- dpkg-divert --package dash --no-rename --divert $distrib --add $dfile
# remove the old equivalent of $distrib, if it existed.
if [ -n "$truename" ]; then
rm -f "$truename"
@@ -58,18 +57,20 @@
diverter=$(dpkg-divert --listpackage $dfile)
truename=$(dpkg-divert --truename $dfile)
- if [ "$diverter" != dash ]; then
+ if [ "$diverter" = dash ]; then
+ # Should not happen. Handle anyway.
+ dpkg-divert --package dash --no-rename --remove "$dfile"
+ if [ -n "$truename" ]; then
+ rm -f "$truename"
+ fi
+ elif [ -n "$diverter" ]; then
# good.
return
fi
# Donate the diversion and sh symlink to the bash package.
ltarget=$(echo $ltarget | sed s/dash/bash/)
- dpkg-divert --package dash --no-rename --remove $dfile
dpkg-divert --package bash --no-rename --divert $distrib --add $dfile
- if [ -n "$truename" ]; then
- rm -f "$truename"
- fi
replace_with_link $dfile $ltarget $distrib
}
@@ -85,7 +86,6 @@
if [ "$diverter" = ash ]; then
dpkg-divert --package ash --no-rename --remove $dfile
- dpkg-divert --package dash --no-rename --divert $distrib --add
$dfile
if [ "$truename" != "$distrib" ] && [ -e "$truename" ]; then
mv "$truename" "$distrib"
@@ -104,6 +104,20 @@
fi
}
+drop_obsolete_diversion() {
+ dfile=$1 ltarget=$2 distrib=${3:-$dfile.distrib}
+ diverter=$(dpkg-divert --listpackage "$dfile")
+ truename=$(dpkg-divert --truename "$dfile")
+ actualtarget=$(readlink "$dfile")
+
+ if [ "$diverter" != dash ] || [ "$truename" != "$distrib" ] || [
"$actualtarget" != "$ltarget" ]; then
+ # Not our diversion or a non-trivial one.
+ return
+ fi
+ dpkg-divert --package dash --no-rename --remove "$dfile"
+ rm -f "$truename"
+}
+
add_shell() {
if ! type add-shell > /dev/null 2>&1; then
return
@@ -124,6 +138,10 @@
/usr/share/man/man1/sh.distrib.1.gz \
/usr/share/man/man1/ash.1.gz
add_shell
+elif [ "$1" = configure ] && dpkg --compare-versions "$2" lt
0.5.11+git20210120+802ebd4-1.1~; then
+ drop_obsolete_diversion /bin/sh dash
+ drop_obsolete_diversion /usr/share/man/man1/sh.1.gz dash.1.gz
/usr/share/man/man1/sh.distrib.1.gz
+ add_shell
elif [ "$1" = configure ] && dpkg --compare-versions "$2" lt 0.4.18; then
add_shell
fi
