users: Fix truncated "From" in account logs

Call `last` with `--fullnames` to avoid truncating values (like IPv6
addresses). We don't rely on a "nicely" (argh) formatted ASCII table
with fixed column widths, but parse the structure.

Flesh out TestAccounts.testAccountLogs to actually test some values on
the page. It was almost empty before. Like in the previous commit, we
can afford to hardcode the expected IPv6 "from" address.

Fixes #21383

pkg/users/account-logs-panel.jsx

@@ -31,7 +31,7 @@ const _ = cockpit.gettext;
 export function AccountLogs({ name }) {
     const [logins, setLogins] = useState([]);
     useInit(() => {
-        cockpit.spawn(["last", "--time-format", "iso", "-n25", name], { environ: ["LC_ALL=C"] })
+        cockpit.spawn(["last", "--time-format", "iso", "-n25", "--fullnames", name], { environ: ["LC_ALL=C"] })
                 .then(data => {
                     let logins = [];
                     data.split('\n').forEach(line => {

test/verify/check-users

@@ -1079,14 +1079,26 @@ class TestAccounts(testlib.MachineCase):
         m.execute("truncate -s0 /var/log/{[bw]tmp,lastlog} /run/utmp")
         m.execute("rm -f /var/lib/lastlog/lastlog2.db /var/lib/wtmpdb/wtmp.db")
 
-        # Login once to create an entry
-        self.login_and_go("/users")
+        # First login: no entries yet
+        self.login_and_go("/users#/admin")
+        # just the header, nothing else
+        b.wait_text("#account-logs", "Login history")
+        self.assertFalse(b.is_present("#account-logs tr"))
         b.logout()
 
+        year = m.execute("date +%Y").strip()
+
+        # second login: one entry from the first one
         self.login_and_go("/users#/admin")
-        b.wait_visible("#account-logs")
         # Header + one line of logins
         b.wait_js_func("ph_count_check", "#account-logs tr", 2)
+        started = b.text("#account-logs [data-label='Started']")
+        ended = b.text("#account-logs [data-label='Ended']")
+        self.assertIn(year, started)
+        self.assertIn(year, ended)
+        self.assertGreaterEqual(ended, started)
+        # this is the correct IP for our CI, and we don't run this on tmt
+        b.wait_text("#account-logs [data-label='From']", "::ffff:172.27.0.2")
 
     def testGroups(self):
         b = self.browser