systemd: Fix relative ln add-wants wrapper

The patch to allow systemd to work with old "ln" versions that don't
support --relative didn't work properly in the the meson-add-wants.sh
script.

This results in all the links in systemd's "*.wants" directories being
broken, e.g.
/usr/lib/systemd/system/multi-user.target.wants/getty.target ->
  ../../../../usr/lib/systemd/system/getty.target
There is one too few ".." in that relative link.

The problem is that the script is called with the link name being either a
file or an existing directory.  In the latter case, ln creates the link in
the directory using the name of the target.  This means the link is one
level deeper than the relative link making code thinks.

The solution used is to only dirname the link, moving up a level, if it's
not a directory, to mimic ln's logic in how it creates links.

Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/systemd/0002-install-don-t-use-ln-relative.patch

@@ -1,4 +1,4 @@
-From ecf3b9baaebda1d9182c22dc504e32ed275d4abb Mon Sep 17 00:00:00 2001
+From 17560d52e9ec0afebbfe31e694870c6433b36f60 Mon Sep 17 00:00:00 2001
 From: Adam Duskett <Adamduskett@outlook.com>
 Date: Sun, 31 Dec 2017 12:46:04 -0500
 Subject: [PATCH] install: don't use ln --relative
@@ -21,17 +21,20 @@ Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
 [aduskett@gmail.com: Added meson.build section and dirname wrapper in add-wants]
 [aduskett@gmail.com: Update for systemd v237]
 Signed-off-by: Adam Duskett <Adamduskett@outlook.com>
+[tpiepho@impinj.com: Fix add-wants wrapper]
+Signed-off-by: Trent Piepho <tpiepho@impinj.com>
 ---
  meson.build                 | 2 +-
  tools/meson-make-symlink.sh | 3 ++-
- units/meson-add-wants.sh    | 5 +++--
- 3 files changed, 6 insertions(+), 4 deletions(-)
+ units/meson-add-wants.sh    | 6 ++++--
+ 3 files changed, 7 insertions(+), 4 deletions(-)
 
 diff --git a/meson.build b/meson.build
-index ddc061c..614201a 100644
+index d4af95a44..d75f2b34c 100644
 --- a/meson.build
 +++ b/meson.build
-@@ -572,6 +572,6 @@ conf.set_quoted('TELINIT', get_option('telinit-path'))
+@@ -586,7 +586,7 @@ endforeach
+ conf.set_quoted('TELINIT', get_option('telinit-path'))
  
  if run_command('ln', '--relative', '--help').returncode() != 0
 -        error('ln does not support --relative')
@@ -40,7 +43,7 @@ index ddc061c..614201a 100644
  
  ############################################################
 diff --git a/tools/meson-make-symlink.sh b/tools/meson-make-symlink.sh
-index 47a5e70..e9002ad 100755
+index 501cd43d4..25e7f89fd 100755
 --- a/tools/meson-make-symlink.sh
 +++ b/tools/meson-make-symlink.sh
 @@ -8,5 +8,6 @@ mkdir -vp "$(dirname "${DESTDIR:-}$2")"
@@ -52,7 +55,7 @@ index 47a5e70..e9002ad 100755
 +        ln -vfs -T "${dds}$1" "${DESTDIR:-}$2"
  fi
 diff --git a/units/meson-add-wants.sh b/units/meson-add-wants.sh
-index dfd287e..8c08283 100755
+index 70f7172ae..bb8155075 100755
 --- a/units/meson-add-wants.sh
 +++ b/units/meson-add-wants.sh
 @@ -14,7 +14,7 @@ case "$target" in
@@ -64,12 +67,13 @@ index dfd287e..8c08283 100755
  
  case "$target" in
          */)
-@@ -25,4 +25,5 @@ case "$target" in
+@@ -25,4 +25,6 @@ case "$target" in
                  ;;
  esac
  
 -ln -vfs --relative "$unitpath" "$dir"
-+dds="$( dirname `printf "%s" "${dir#${DESTDIR:-}}" |sed -r -e 's:/+[^/]+:../:g; s:/$::'` )"
++[ ! -d "${dir}" ] && linkdir=`dirname "${dir}"` || linkdir="${dir}"
++dds="$(printf "%s" "${linkdir#${DESTDIR:-}}" |sed -r -e 's:/+[^/]+:../:g; s:/$::')"
 +ln -vfs "$dds$unitpath" "$dir"
 -- 
 2.14.3