[gnome-software/wip/addons-can-be-NULL] packagekit: Check for non-NULL addons returned by gs_app_dup_addons()

[Milan Crha <mcrha src gnome org>]

commit 617040440d207b45479d907671663489d25f6794
Author: Milan Crha <mcrha redhat com>
Date:   Fri May 13 09:28:16 2022 +0200

    packagekit: Check for non-NULL addons returned by gs_app_dup_addons()
    
    Otherwise a runtime warning is printed on the console.

 plugins/packagekit/gs-plugin-packagekit.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/plugins/packagekit/gs-plugin-packagekit.c b/plugins/packagekit/gs-plugin-packagekit.c
index ca630e60b..863469b93 100644
--- a/plugins/packagekit/gs-plugin-packagekit.c
+++ b/plugins/packagekit/gs-plugin-packagekit.c
@@ -621,7 +621,7 @@ gs_plugin_app_install (GsPlugin *plugin,
 
                gs_app_set_state (app, GS_APP_STATE_INSTALLING);
 
-               for (i = 0; i < gs_app_list_length (addons); i++) {
+               for (i = 0; addons != NULL && i < gs_app_list_length (addons); i++) {
                        GsApp *addon = gs_app_list_index (addons, i);
                        if (gs_app_get_to_be_installed (addon))
                                gs_app_set_state (addon, GS_APP_STATE_INSTALLING);
@@ -636,7 +636,7 @@ gs_plugin_app_install (GsPlugin *plugin,
                                                         error);
                g_mutex_unlock (&self->task_mutex);
                if (!gs_plugin_packagekit_results_valid (results, error)) {
-                       for (i = 0; i < gs_app_list_length (addons); i++) {
+                       for (i = 0; addons != NULL && i < gs_app_list_length (addons); i++) {
                                GsApp *addon = gs_app_list_index (addons, i);
                                if (gs_app_get_state (addon) == GS_APP_STATE_INSTALLING)
                                        gs_app_set_state_recover (addon);
@@ -646,7 +646,7 @@ gs_plugin_app_install (GsPlugin *plugin,
                }
 
                /* state is known */
-               for (i = 0; i < gs_app_list_length (addons); i++) {
+               for (i = 0; addons != NULL && i < gs_app_list_length (addons); i++) {
                        GsApp *addon = gs_app_list_index (addons, i);
                        if (gs_app_get_state (addon) == GS_APP_STATE_INSTALLING) {
                                gs_app_set_state (addon, GS_APP_STATE_INSTALLED);