shared/path-lookup: rearrange paths in --global mode to match --user mode

It's not good if the paths are in different order. With --user, we expect
more paths, but it must be a strict superset, and the order for the ones
that appear in both sets must be the same.

$  diff -u <(build/systemd-analyze --global unit-paths) <(build/systemd-analyze --user unit-paths)|colordiff
--- /proc/self/fd/14	2018-02-08 14:11:45.425353107 +0100
+++ /proc/self/fd/15	2018-02-08 14:11:45.426353116 +0100
@@ -1,6 +1,17 @@
+/home/zbyszek/.config/systemd/system.control
+/run/user/1000/systemd/system.control
+/run/user/1000/systemd/transient
+/run/user/1000/systemd/generator.early
+/home/zbyszek/.config/systemd/user
 /etc/systemd/user
+/run/user/1000/systemd/user
 /run/systemd/user
+/run/user/1000/systemd/generator
+/home/zbyszek/.local/share/systemd/user
+/home/zbyszek/.local/share/flatpak/exports/share/systemd/user
+/var/lib/flatpak/exports/share/systemd/user
 /usr/local/share/systemd/user
 /usr/share/systemd/user
 /usr/local/lib/systemd/user
 /usr/lib/systemd/user
+/run/user/1000/systemd/generator.late

A test is added so that we don't regress on this.

1 files changed, 32 insertions, 0 deletions

diff --git a/src/test/test-path-lookup.c b/src/test/test-path-lookup.c
index 834b061980..0541033d77 100644
--- a/src/test/test-path-lookup.c
+++ b/src/test/test-path-lookup.c
@@ -52,6 +52,36 @@ static void test_paths(UnitFileScope scope) {
         assert_se(rm_rf(template, REMOVE_ROOT|REMOVE_PHYSICAL) >= 0);
 }
 
+static void test_user_and_global_paths(void) {
+        _cleanup_lookup_paths_free_ LookupPaths lp_global = {}, lp_user = {};
+        char **u, **g, **p;
+        unsigned k = 0;
+
+        assert_se(unsetenv("SYSTEMD_UNIT_PATH") == 0);
+
+        assert_se(lookup_paths_init(&lp_global, UNIT_FILE_GLOBAL, 0, NULL) == 0);
+        assert_se(lookup_paths_init(&lp_user, UNIT_FILE_USER, 0, NULL) == 0);
+        g = lp_global.search_path;
+        u = lp_user.search_path;
+
+        /* Go over all entries in global search path, and verify
+         * that they also exist in the user search path. Skip any
+         * entries in user search path which don't exist in the global
+         * one, but not vice versa. */
+        log_info("/* %s */", __func__);
+        STRV_FOREACH(p, g) {
+                while (u[k] && !streq(*p, u[k])) {
+                        log_info("+ %s", u[k]);
+                        k++;
+                }
+                log_info("  %s", *p);
+                assert(u[k]); /* If NULL, we didn't find a matching entry */
+                k++;
+        }
+        STRV_FOREACH(p, u + k)
+                log_info("+ %s", *p);
+}
+
 static void print_generator_binary_paths(UnitFileScope scope) {
         _cleanup_strv_free_ char **paths;
         char **dir;
@@ -72,6 +102,8 @@ int main(int argc, char **argv) {
         test_paths(UNIT_FILE_USER);
         test_paths(UNIT_FILE_GLOBAL);
 
+        test_user_and_global_paths();
+
         print_generator_binary_paths(UNIT_FILE_SYSTEM);
         print_generator_binary_paths(UNIT_FILE_USER);