[Libosinfo] [libosinfo] osinfo-query: return failure when no matches are found

[Fabiano Fidêncio]

According to `man osinfo-query`: "The exit status will be 0 if matching
entries were found, or 1 if not matches were found". So, let's adapt the
program in order to match the manual.

Also, this patch was written keeping the current behavior about printing
the Short ID, Name, Version, ID table.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1351718

Signed-off-by: Fabiano Fidêncio <fidencio at redhat.com>
---
 tools/osinfo-query.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/tools/osinfo-query.c b/tools/osinfo-query.c
index 66f49e2..48e792f 100644
--- a/tools/osinfo-query.c
+++ b/tools/osinfo-query.c
@@ -331,6 +331,9 @@ static gboolean print_results_text(OsinfoList *list,
     }
     g_print("\n");
 
+    if (tmp == NULL)
+        goto end;
+
     while (tmp) {
         OsinfoEntity *entity = OSINFO_ENTITY(tmp->data);
 
@@ -338,9 +341,10 @@ static gboolean print_results_text(OsinfoList *list,
         tmp = tmp->next;
     }
 
+    ret = TRUE;
 
+end:
     g_list_free(entities);
-    ret = TRUE;
     // cleanup:
     return ret;
 }
@@ -458,7 +462,13 @@ gint main(gint argc, gchar **argv)
 
     osinfo_list_add_filtered(results, entities, filter);
 
-    print_results_text(results, labels, sortKey);
+    if (!print_results_text(results, labels, sortKey)) {
+        /*
+         * The os wasn't found, no need to print an error,
+         * just be sure to return EXIT_FAILURE.
+         */
+        goto error;
+    }
 
     ret = EXIT_SUCCESS;
 
-- 
2.7.4