diff -Naru fwupd-1.2.9/src/fu-keyring-gpg.c fwupd-1.2.9-new/src/fu-keyring-gpg.c
--- fwupd-1.2.9/src/fu-keyring-gpg.c	2019-05-20 18:18:00.000000000 +0800
+++ fwupd-1.2.9-new/src/fu-keyring-gpg.c	2022-07-25 10:51:37.434242000 +0800
@@ -297,6 +297,13 @@
 				     "no result record from libgpgme");
 		return NULL;
 	}
+	if (result->signatures == NULL) {
+		g_set_error_literal (error,
+				     FWUPD_ERROR,
+				     FWUPD_ERROR_INTERNAL,
+				     "no signatures from libgpgme");
+		return NULL;
+	}
 
 	/* look at each signature */
 	for (s = result->signatures; s != NULL ; s = s->next ) {