installation: Check user installation in list_unused_refs()

Currently flatpak_installation_list_unused_refs() only considers one
installation when determining which runtimes are unused. But apps in a
per-user installation can use a runtime in the system installation, so
check for this scenario as well. Also check related scenarios such as
a user-installed runtime with a system-installed extension, though that
seems less likely to happen in practice.

I realize now after writing this that it's also possible to have runtime
dependencies across system installations (see
flatpak_transaction_add_default_dependency_sources()). So we may need a
more generalized mechanism here eventually.

Note that this is limited in only being able to check the current user's
installation. On multi-user systems there may be another user sharing
the system installation.

A unit test is included, though it doesn't cover every edge case.

4 files changed, 267 insertions, 63 deletions

diff --git a/common/flatpak-dir-private.h b/common/flatpak-dir-private.h
index 7a6d7080..543e94a0 100644
--- a/common/flatpak-dir-private.h
+++ b/common/flatpak-dir-private.h
@@ -963,6 +963,7 @@ GPtrArray * flatpak_dir_find_local_related_for_metadata (FlatpakDir   *self,
                                                          GError      **error);
 GPtrArray * flatpak_dir_find_local_related (FlatpakDir   *self,
                                             const char   *ref,
+                                            FlatpakDir   *ref_dir,
                                             const char   *remote_name,
                                             gboolean      deployed,
                                             GCancellable *cancellable,
diff --git a/common/flatpak-dir.c b/common/flatpak-dir.c
index 492f1bcb..5d56a87d 100644
--- a/common/flatpak-dir.c
+++ b/common/flatpak-dir.c
@@ -14124,6 +14124,7 @@ flatpak_dir_find_local_related_for_metadata (FlatpakDir   *self,
 GPtrArray *
 flatpak_dir_find_local_related (FlatpakDir   *self,
                                 const char   *ref,
+                                FlatpakDir   *ref_dir,
                                 const char   *remote_name,
                                 gboolean      deployed,
                                 GCancellable *cancellable,
@@ -14140,9 +14141,14 @@ flatpak_dir_find_local_related (FlatpakDir   *self,
   if (!flatpak_dir_ensure_repo (self, cancellable, error))
     return NULL;
 
+  /* If @ref_dir is non-NULL it will be used for getting the metadata for @ref
+   * but not for finding related refs */
+  if (ref_dir != NULL && !flatpak_dir_ensure_repo (ref_dir, cancellable, error))
+    return NULL;
+
   if (deployed)
     {
-      deploy_dir = flatpak_dir_get_if_deployed (self, ref, NULL, cancellable);
+      deploy_dir = flatpak_dir_get_if_deployed (ref_dir ? ref_dir : self, ref, NULL, cancellable);
       if (deploy_dir == NULL)
         {
           g_set_error (error, FLATPAK_ERROR, FLATPAK_ERROR_NOT_INSTALLED,
@@ -14165,7 +14171,7 @@ flatpak_dir_find_local_related (FlatpakDir   *self,
     }
   else
     {
-      g_autoptr(GVariant) commit_data = flatpak_dir_read_latest_commit (self, remote_name, ref, &checksum, NULL, NULL);
+      g_autoptr(GVariant) commit_data = flatpak_dir_read_latest_commit (ref_dir ? ref_dir : self, remote_name, ref, &checksum, NULL, NULL);
       if (commit_data)
         {
           g_autoptr(GVariant) commit_metadata = g_variant_get_child_value (commit_data, 0);
diff --git a/common/flatpak-installation.c b/common/flatpak-installation.c
index f18622fb..89437934 100644
--- a/common/flatpak-installation.c
+++ b/common/flatpak-installation.c
@@ -2737,7 +2737,7 @@ flatpak_installation_list_installed_related_refs_sync (FlatpakInstallation *self
   if (dir == NULL)
     return NULL;
 
-  related = flatpak_dir_find_local_related (dir, ref, remote_name, TRUE,
+  related = flatpak_dir_find_local_related (dir, ref, NULL, remote_name, TRUE,
                                             cancellable, error);
   if (related == NULL)
     return NULL;
@@ -2884,17 +2884,25 @@ flatpak_installation_run_triggers (FlatpakInstallation *self,
 
 
 static void
-find_used_refs (FlatpakDir *dir,
-                GHashTable *used_refs,
-                const char *ref,
-                const char *origin)
+find_used_related_refs (FlatpakDir *dir,
+                        FlatpakDir *system_dir, /* nullable */
+                        GHashTable *used_refs,
+                        const char *ref,
+                        const char *origin)
 {
   g_autoptr(GPtrArray) related = NULL;
   int i;
 
-  g_hash_table_add (used_refs, g_strdup (ref));
+  if (system_dir == NULL)
+    g_hash_table_add (used_refs, g_strdup (ref));
+
+  /* If @system_dir is non-NULL, that means @ref exists in @dir but we should
+   * look in @system_dir for related things */
+  if (system_dir != NULL)
+    related = flatpak_dir_find_local_related (system_dir, ref, dir, origin, TRUE, NULL, NULL);
+  else
+    related = flatpak_dir_find_local_related (dir, ref, NULL, origin, TRUE, NULL, NULL);
 
-  related = flatpak_dir_find_local_related (dir, ref, origin, TRUE, NULL, NULL);
   if (related == NULL)
     return;
 
@@ -2902,15 +2910,142 @@ find_used_refs (FlatpakDir *dir,
     {
       FlatpakRelated *rel = g_ptr_array_index (related, i);
 
+      /* Check if this related ref is present in @dir, which implies the one
+       * in @system_dir is NOT the one being used. */
+      if (system_dir != NULL)
+        {
+          g_autoptr(FlatpakDeploy) user_related_deploy = flatpak_dir_load_deployed (dir, rel->ref, NULL, NULL, NULL);
+          if (user_related_deploy != NULL)
+            continue;
+        }
+
       if (!rel->auto_prune && !g_hash_table_contains (used_refs, rel->ref))
         {
           g_autofree char *related_origin = NULL;
 
           g_hash_table_add (used_refs, g_strdup (rel->ref));
 
-          related_origin = flatpak_dir_get_origin (dir, rel->ref, NULL, NULL);
+          related_origin = flatpak_dir_get_origin (system_dir ? system_dir : dir, rel->ref, NULL, NULL);
           if (related_origin != NULL)
-            find_used_refs (dir, used_refs, rel->ref, related_origin);
+            find_used_related_refs (system_dir ? system_dir : dir, NULL, used_refs, rel->ref, related_origin);
+        }
+    }
+}
+
+static void
+find_used_refs_for_apps (FlatpakDir  *dir,
+                         FlatpakDir  *system_dir, /* nullable */
+                         char       **app_refs,
+                         const char  *arch,
+                         GHashTable  *used_runtimes,
+                         GHashTable  *used_refs)
+{
+  /* Check for related refs and runtimes and sdks for each app in @app_refs.
+   * The apps exist in @dir but if @system_dir is set that's where we check for
+   * the related/runtime/sdk, and if @system_dir is set we check that said
+   * runtime does not exist in @dir, so the one in @system_dir is probably the
+   * one being used. */
+  int i;
+  for (i = 0; app_refs[i] != NULL; i++)
+    {
+      const char *ref = app_refs[i];
+      g_autoptr(FlatpakDeploy) deploy = NULL;
+      g_autofree char *origin = NULL;
+      g_autofree char *runtime = NULL;
+      g_autofree char *sdk = NULL;
+      g_autoptr(GKeyFile) metakey = NULL;
+      g_auto(GStrv) parts = g_strsplit (ref, "/", -1);
+
+      if (arch != NULL && strcmp (parts[2], arch) != 0)
+        continue;
+
+      deploy = flatpak_dir_load_deployed (dir, ref, NULL, NULL, NULL);
+      if (deploy == NULL)
+        continue;
+
+      origin = flatpak_dir_get_origin (dir, ref, NULL, NULL);
+      if (origin == NULL)
+        continue;
+
+      find_used_related_refs (dir, system_dir, used_refs, ref, origin);
+
+      metakey = flatpak_deploy_get_metadata (deploy);
+      runtime = g_key_file_get_string (metakey, "Application", "runtime", NULL);
+      if (runtime)
+        {
+          g_autoptr(FlatpakDeploy) runtime_deploy = NULL;
+          g_autoptr(FlatpakDeploy) user_runtime_deploy = NULL;
+          if (system_dir != NULL)
+            {
+              g_autofree char *runtime_ref = g_strconcat ("runtime/", runtime, NULL);
+              runtime_deploy = flatpak_dir_load_deployed (system_dir, runtime_ref, NULL, NULL, NULL);
+              user_runtime_deploy = flatpak_dir_load_deployed (dir, runtime_ref, NULL, NULL, NULL);
+            }
+
+          if (system_dir == NULL || (runtime_deploy != NULL && user_runtime_deploy == NULL))
+            g_hash_table_add (used_runtimes, g_steal_pointer (&runtime));
+        }
+
+      sdk = g_key_file_get_string (metakey, "Application", "sdk", NULL);
+      if (sdk)
+        {
+          g_autoptr(FlatpakDeploy) sdk_deploy = NULL;
+          g_autoptr(FlatpakDeploy) user_sdk_deploy = NULL;
+          if (system_dir != NULL)
+            {
+              g_autofree char *sdk_ref = g_strconcat ("runtime/", sdk, NULL);
+              sdk_deploy = flatpak_dir_load_deployed (system_dir, sdk_ref, NULL, NULL, NULL);
+              user_sdk_deploy = flatpak_dir_load_deployed (dir, sdk_ref, NULL, NULL, NULL);
+            }
+
+          if (system_dir == NULL || (sdk_deploy != NULL && user_sdk_deploy == NULL))
+            g_hash_table_add (used_runtimes, g_steal_pointer (&sdk));
+        }
+    }
+}
+
+static void
+find_used_refs_for_runtimes (FlatpakDir *dir,
+                             FlatpakDir *system_dir,
+                             GHashTable *runtimes,
+                             GHashTable *used_refs)
+{
+  /* For each runtime in @runtimes, if it's in @dir, add the related refs and
+   * sdk to @used_refs. If @system_dir is set that's where we look for
+   * related refs and sdk related refs; the sdk could be in either dir. */
+  GLNX_HASH_TABLE_FOREACH (runtimes, const char *, runtime)
+    {
+      g_autofree char *runtime_ref = g_strconcat ("runtime/", runtime, NULL);
+      g_autoptr(FlatpakDeploy) deploy = NULL;
+      g_autofree char *origin = NULL;
+      g_autofree char *sdk = NULL;
+      g_autoptr(GKeyFile) metakey = NULL;
+
+      deploy = flatpak_dir_load_deployed (dir, runtime_ref, NULL, NULL, NULL);
+      if (deploy == NULL)
+        continue;
+
+      origin = flatpak_dir_get_origin (dir, runtime_ref, NULL, NULL);
+      if (origin == NULL)
+        continue;
+
+      find_used_related_refs (dir, system_dir, used_refs, runtime_ref, origin);
+
+      metakey = flatpak_deploy_get_metadata (deploy);
+      sdk = g_key_file_get_string (metakey, "Runtime", "sdk", NULL);
+      if (sdk)
+        {
+          g_autofree char *sdk_ref = g_strconcat ("runtime/", sdk, NULL);
+          g_autofree char *sdk_origin = flatpak_dir_get_origin (dir, sdk_ref, NULL, NULL);
+          if (sdk_origin)
+            find_used_related_refs (dir, system_dir, used_refs, sdk_ref, sdk_origin);
+
+          if (system_dir != NULL && sdk_origin == NULL)
+            {
+              g_autofree char *system_sdk_origin = flatpak_dir_get_origin (system_dir, sdk_ref, NULL, NULL);
+              if (system_sdk_origin)
+                find_used_related_refs (system_dir, NULL, used_refs, sdk_ref, sdk_origin);
+            }
         }
     }
 }
@@ -2962,67 +3097,46 @@ flatpak_installation_list_unused_refs (FlatpakInstallation *self,
   refs_hash = g_hash_table_new (g_str_hash, g_str_equal);
   refs = g_ptr_array_new_with_free_func (g_object_unref);
 
-  for (i = 0; app_refs[i] != NULL; i++)
+  /* For each app, note the runtime, sdk, and related refs */
+  find_used_refs_for_apps (dir, NULL, app_refs, arch, used_runtimes, used_refs);
+
+  /* If @self is a system installation, also check the per-user installation
+   * for any apps there using runtimes in the system installation or runtimes
+   * there with sdks or extensions in the system installation. Only do so if
+   * the per-user installation exists; it wouldn't make sense to create it here
+   * if not.
+   */
+  if (!flatpak_dir_is_user (dir))
     {
-      const char *ref = app_refs[i];
-      g_autoptr(FlatpakDeploy) deploy = NULL;
-      g_autofree char *origin = NULL;
-      g_autofree char *runtime = NULL;
-      g_autofree char *sdk = NULL;
-      g_autoptr(GKeyFile) metakey = NULL;
-      g_auto(GStrv) parts = g_strsplit (ref, "/", -1);
+      g_autoptr(GFile) user_base_dir = flatpak_get_user_base_dir_location ();
 
-      if (arch != NULL && strcmp (parts[2], arch) != 0)
-        continue;
+      if (g_file_query_exists (user_base_dir, cancellable))
+        {
+          g_autoptr(FlatpakDir) user_dir = flatpak_dir_get_user ();
+          g_auto(GStrv) user_app_refs = NULL;
+          g_auto(GStrv) user_runtime_refs = NULL;
+          g_autoptr(GHashTable) user_runtimes = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, NULL);
 
-      deploy = flatpak_dir_load_deployed (dir, ref, NULL, NULL, NULL);
-      if (deploy == NULL)
-        continue;
+          if (!flatpak_dir_list_refs (user_dir, "app", &user_app_refs, cancellable, error))
+            return NULL;
 
-      origin = flatpak_dir_get_origin (dir, ref, NULL, NULL);
-      if (origin == NULL)
-        continue;
+          find_used_refs_for_apps (user_dir, dir, user_app_refs, arch, used_runtimes, used_refs);
 
-      find_used_refs (dir, used_refs, ref, origin);
+          if (!flatpak_dir_list_refs (user_dir, "runtime", &user_runtime_refs, cancellable, error))
+            return NULL;
 
-      metakey = flatpak_deploy_get_metadata (deploy);
-      runtime = g_key_file_get_string (metakey, "Application", "runtime", NULL);
-      if (runtime)
-        g_hash_table_add (used_runtimes, g_steal_pointer (&runtime));
+          for (i = 0; user_runtime_refs[i] != NULL; i++)
+            {
+              const char *ref = user_runtime_refs[i];
+              g_assert (g_str_has_prefix (ref, "runtime/"));
+              g_hash_table_add (user_runtimes, (char *)ref + strlen ("runtime/"));
+            }
 
-      sdk = g_key_file_get_string (metakey, "Application", "sdk", NULL);
-      if (sdk)
-        g_hash_table_add (used_runtimes, g_steal_pointer (&sdk));
+          find_used_refs_for_runtimes (user_dir, dir, user_runtimes, used_refs);
+        }
     }
 
-  GLNX_HASH_TABLE_FOREACH (used_runtimes, const char *, runtime)
-  {
-    g_autofree char *runtime_ref = g_strconcat ("runtime/", runtime, NULL);
-    g_autoptr(FlatpakDeploy) deploy = NULL;
-    g_autofree char *origin = NULL;
-    g_autofree char *sdk = NULL;
-    g_autoptr(GKeyFile) metakey = NULL;
-
-    deploy = flatpak_dir_load_deployed (dir, runtime_ref, NULL, NULL, NULL);
-    if (deploy == NULL)
-      continue;
-
-    origin = flatpak_dir_get_origin (dir, runtime_ref, NULL, NULL);
-    if (origin == NULL)
-      continue;
-
-    find_used_refs (dir, used_refs, runtime_ref, origin);
-
-    metakey = flatpak_deploy_get_metadata (deploy);
-    sdk = g_key_file_get_string (metakey, "Runtime", "sdk", NULL);
-    if (sdk)
-      {
-        g_autofree char *sdk_ref = g_strconcat ("runtime/", sdk, NULL);
-        g_autofree char *sdk_origin = flatpak_dir_get_origin (dir, sdk_ref, NULL, NULL);
-        if (sdk_origin)
-          find_used_refs (dir, used_refs, sdk_ref, sdk_origin);
-      }
-  }
+  find_used_refs_for_runtimes (dir, NULL, used_runtimes, used_refs);
 
   for (i = 0; runtime_refs[i] != NULL; i++)
     {
diff --git a/tests/testlibrary.c b/tests/testlibrary.c
index 1f760c6e..8b1b0c02 100644
--- a/tests/testlibrary.c
+++ b/tests/testlibrary.c
@@ -4331,6 +4331,88 @@ test_installation_unused_refs_excludes_pins (void)
   g_assert_cmpint (refs->len, ==, 0);
 }
 
+static void
+test_installation_unused_refs_across_installations (void)
+{
+  g_autoptr(FlatpakInstallation) system_inst = NULL;
+  g_autoptr(FlatpakInstallation) user_inst = NULL;
+  g_autoptr(FlatpakTransaction) transaction = NULL;
+  g_autoptr(GPtrArray) refs = NULL;
+  g_autoptr(GError) error = NULL;
+  g_autofree char *runtime = NULL;
+  g_autofree char *app = NULL;
+  FlatpakInstalledRef *unused_ref;
+  gboolean res;
+
+  runtime = g_strdup_printf ("runtime/org.test.Platform/%s/master",
+                             flatpak_get_default_arch ());
+  app = g_strdup_printf ("app/org.test.Hello/%s/master",
+                         flatpak_get_default_arch ());
+
+  system_inst = flatpak_installation_new_system (NULL, &error);
+  g_assert_no_error (error);
+  g_assert_nonnull (system_inst);
+
+  user_inst = flatpak_installation_new_user (NULL, &error);
+  g_assert_no_error (error);
+  g_assert_nonnull (user_inst);
+
+  empty_installation (system_inst);
+  empty_installation (user_inst);
+
+  add_remote_system ("test-runtime-only", NULL);
+
+  transaction = flatpak_transaction_new_for_installation (system_inst, NULL, &error);
+  g_assert_no_error (error);
+  g_assert_nonnull (transaction);
+
+  res = flatpak_transaction_add_install (transaction, "test-runtime-only-repo", runtime, NULL, &error);
+  g_assert_no_error (error);
+  g_assert_true (res);
+
+  res = flatpak_transaction_run (transaction, NULL, &error);
+  g_assert_no_error (error);
+  g_assert_true (res);
+  g_clear_object (&transaction);
+
+  /* Undo the pinning that happened as a side effect of the install */
+  const char *argv[] = { "flatpak", "pin", "--system", "--remove", runtime, NULL };
+  run_test_subprocess ((char **) argv, RUN_TEST_SUBPROCESS_DEFAULT);
+  flatpak_installation_drop_caches (system_inst, NULL, &error);
+  g_assert_no_error (error);
+
+  /* The runtime should show as unused */
+  refs = flatpak_installation_list_unused_refs (system_inst, NULL, NULL, &error);
+  g_assert_nonnull (refs);
+  g_assert_no_error (error);
+  g_assert_cmpint (refs->len, ==, 1);
+  unused_ref = g_ptr_array_index (refs, 0);
+  g_assert_cmpstr (flatpak_ref_get_name (FLATPAK_REF (unused_ref)), ==, "org.test.Platform");
+  g_clear_pointer (&refs, g_ptr_array_unref);
+
+  /* Install an app in the user installation that uses the runtime in the
+   * system installation */
+  transaction = flatpak_transaction_new_for_installation (user_inst, NULL, &error);
+  g_assert_no_error (error);
+  g_assert_nonnull (transaction);
+
+  flatpak_transaction_add_dependency_source (transaction, system_inst);
+
+  res = flatpak_transaction_add_install (transaction, repo_name, app, NULL, &error);
+  g_assert_no_error (error);
+  g_assert_true (res);
+
+  res = flatpak_transaction_run (transaction, NULL, &error);
+  g_assert_no_error (error);
+  g_assert_true (res);
+
+  /* Now the runtime should be used */
+  refs = flatpak_installation_list_unused_refs (system_inst, NULL, NULL, &error);
+  g_assert_nonnull (refs);
+  g_assert_no_error (error);
+  g_assert_cmpint (refs->len, ==, 0);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -4382,6 +4464,7 @@ main (int argc, char *argv[])
   g_test_add_func ("/library/installation-no-interaction", test_installation_no_interaction);
   g_test_add_func ("/library/installation-unused-refs", test_installation_unused_refs);
   g_test_add_func ("/library/installation-unused-refs-excludes-pins", test_installation_unused_refs_excludes_pins);
+  g_test_add_func ("/library/installation-unused-refs-across-installations", test_installation_unused_refs_across_installations);
 
   global_setup ();