openpgp: Raise an exception of importing yields no keys

Signed-off-by: Michał Górny <mgorny@gentoo.org>

Author: mgorny

gemato/openpgp.py

@@ -545,13 +545,15 @@ def import_key(self, keyfile, trust=True):
             keyfile.read(),
             raise_on_error=OpenPGPKeyImportError)
 
+        fprs = set()
+        for line in out.splitlines():
+            if line.startswith(b'[GNUPG:] IMPORT_OK'):
+                fprs.add(line.split(b' ')[3].decode('ASCII'))
+        if not fprs:
+            raise OpenPGPKeyImportError("No keys imported")
+
         if trust:
-            fprs = set()
-            for line in out.splitlines():
-                if line.startswith(b'[GNUPG:] IMPORT_OK'):
-                    fprs.add(line.split(b' ')[3].decode('ASCII'))
             self._trusted_keys.update(fprs)
-
             ownertrust = ''.join(f'{fpr}:6:\n' for fpr in fprs).encode('utf8')
             exitst, out, err = self._spawn_gpg(
                 [GNUPG, '--batch', '--import-ownertrust'],