Simplify the meaning of %s

The rules governing %s where just too complicated. First of
all, looking at $SHELL is dangerous. For systemd --system,
it usually wouldn't be set. But it could be set if the admin
first started a debug shell, let's say /sbin/sash, and then
launched systemd from it. This shouldn't influence how daemons
are started later on, so is better ignored. Similar reasoning
holds for session mode. Some shells set $SHELL, while other
set it only when it wasn't set previously (e.g. zsh). This
results in fragility that is better avoided by ignoring $SHELL
totally.

With $SHELL out of the way, simplify things by saying that
%s==/bin/sh for root, and the configured shell otherwise.
get_shell() is the only caller, so it can be inlined.

Fixes one issue seen with 'make check'.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/test/test-unit-name.c b/src/test/test-unit-name.c
index 7bd99d31c8..0b6b56394e 100644
--- a/src/test/test-unit-name.c
+++ b/src/test/test-unit-name.c
@@ -164,7 +164,7 @@ static void test_unit_printf(void) {
         expect(u, "%u", root->pw_name);
         expect(u, "%U", root_uid);
         expect(u, "%h", root->pw_dir);
-        expect(u, "%s", root->pw_shell);
+        expect(u, "%s", "/bin/sh");
         expect(u, "%m", mid);
         expect(u, "%b", bid);
         expect(u, "%H", host);
@@ -184,7 +184,7 @@ static void test_unit_printf(void) {
         expect(u2, "%u", root->pw_name);
         expect(u2, "%U", root_uid);
         expect(u2, "%h", root->pw_dir);
-        expect(u2, "%s", root->pw_shell);
+        expect(u2, "%s", "/bin/sh");
         expect(u2, "%m", mid);
         expect(u2, "%b", bid);
         expect(u2, "%H", host);