client: Fix settings crash on missing net identity

When fetching the client identity in Network settings, make sure the
identity exists before trying to convert it into a CertIdentity.

This resolves a crash if an identity is deleted improperly or if no
identities are specified.

Test case:
1.  Clear the configuration for Quassel monolithic
2.  Start Quassel monolithic
3.  Cancel the setup wizard (before creating any identity)
4.  Go to Settings -> Configure Quassel... (F7)
5.  Navigate to IRC -> Identities, confirm that no identity exists
6.  Navigate to IRC -> Networks
7.  Add a new network (details don't matter)
8.  Observe results

NOTE: This fix was contributed by "kater" on the Quassel IRC bug
tracker.  I'm not sure of a better way to provide attribution, as I
don't know if they want their email address part of Quassel's public
record.

See the original patch here:
https://bugs.quassel-irc.org/issues/1409

Fixes #1409

diff --git a/src/qtui/settingspages/networkssettingspage.cpp b/src/qtui/settingspages/networkssettingspage.cpp
index 0f67de2..d4fdca1 100644 (file)
--- a/src/qtui/settingspages/networkssettingspage.cpp
+++ b/src/qtui/settingspages/networkssettingspage.cpp
@@ -590,12 +590,21 @@ void NetworksSettingsPage::displayNetwork(NetworkId id)
         // this is only needed when the core supports SASL EXTERNAL
         if (Client::isCoreFeatureEnabled(Quassel::Feature::SaslExternal)) {
             if (_cid) {
+                // Clean up existing CertIdentity
                 disconnect(_cid, &CertIdentity::sslSettingsUpdated, this, &NetworksSettingsPage::sslUpdated);
                 delete _cid;
+                _cid = nullptr;
+            }
+            auto *identity = Client::identity(info.identity);
+            if (identity) {
+                // Connect new CertIdentity
+                _cid = new CertIdentity(*identity, this);
+                _cid->enableEditSsl(true);
+                connect(_cid, &CertIdentity::sslSettingsUpdated, this, &NetworksSettingsPage::sslUpdated);
+            }
+            else {
+                qWarning() << "NetworksSettingsPage::displayNetwork can't find Identity for IdentityId:" << info.identity;
             }
-            _cid = new CertIdentity(*Client::identity(info.identity), this);
-            _cid->enableEditSsl(true);
-            connect(_cid, &CertIdentity::sslSettingsUpdated, this, &NetworksSettingsPage::sslUpdated);
         }
 
         ui.identityList->setCurrentIndex(ui.identityList->findData(info.identity.toInt()));