Return "unknown" as expiration date or compliance of remote keys

For remote keys the compliance cannot be checked. Moreover, keyservers
return an empty expiration date (which is parsed as 0).

GnuPG-bug-id: 6201

src/utils/formatting.cpp

@@ -577,7 +577,12 @@ QString Formatting::accessibleDate(const QDate &date)
 
 QString Formatting::expirationDateString(const Key &key, const QString &noExpiration)
 {
-    return expiration_date_string(key.subkey(0), noExpiration);
+    // if key is remote but has a non-zero expiration date (e.g. a key looked up via WKD),
+    // then we assume that the date is valid; if the date is zero for a remote key, then
+    // we don't know if it's unknown or unlimited
+    return isRemoteKey(key) && (key.subkey(0).expirationTime() == 0) //
+        ? i18nc("@info the expiration date of the key is unknown", "unknown")
+        : expiration_date_string(key.subkey(0), noExpiration);
 }
 
 QString Formatting::expirationDateString(const Subkey &subkey, const QString &noExpiration)
@@ -607,7 +612,12 @@ QDate Formatting::expirationDate(const UserID::Signature &sig)
 
 QString Formatting::accessibleExpirationDate(const Key &key, const QString &noExpiration)
 {
-    return accessibleExpirationDate(key.subkey(0), noExpiration);
+    // if key is remote but has a non-zero expiration date (e.g. a key looked up via WKD),
+    // then we assume that the date is valid; if the date is zero for a remote key, then
+    // we don't know if it's unknown or unlimited
+    return isRemoteKey(key) && (key.subkey(0).expirationTime() == 0) //
+        ? i18nc("@info the expiration date of the key is unknown", "unknown")
+        : accessibleExpirationDate(key.subkey(0), noExpiration);
 }
 
 QString Formatting::accessibleExpirationDate(const Subkey &subkey, const QString &noExpiration)
@@ -1170,7 +1180,9 @@ QString Formatting::complianceStringForKey(const GpgME::Key &key)
     // There will likely be more in the future for other institutions
     // for now we only have DE-VS
     if (DeVSCompliance::isCompliant()) {
-        return DeVSCompliance::name(uidsHaveFullValidity(key) && isKeyDeVs(key));
+        return isRemoteKey(key) //
+            ? i18nc("@info the compliance of the key with certain requirements is unknown", "unknown")
+            : DeVSCompliance::name(uidsHaveFullValidity(key) && isKeyDeVs(key));
     }
     return QString();
 }