Fix connect-time username prompt never reaching SSH/RDP authentication

The username entered at the connect-time prompt (added for issue #21)
was updating SessionTab's own in-memory Profile copy, but
SshSessionBackend/RdpSessionBackend are constructed with -- and only
ever read from -- their own separate Profile copy on a worker thread,
which never saw that edit. Authentication was still built from the
original (blank) username regardless of what was typed into the
prompt.

SessionConnectOptions gains a username field, populated by SessionTab
on every connect attempt and threaded through the same way password
already is; both backends now prefer options.username over
profile().username. Covered by a new SSH regression test using an
exact-match fixture host that only succeeds for a specific
user@host target.

Bump version to v2026.9.16.5.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/fixtures/fake_ssh.sh

@@ -6,6 +6,22 @@
 # host, optionally as user@host, as the final argument).
 for arg in "$@"; do
     case "$arg" in
+        prompted-user@requireuser)
+            # Only the exact user@host below is accepted -- used to prove a
+            # username supplied via SessionConnectOptions (prompted for at
+            # connect time because the saved profile's own username was
+            # blank) actually reaches the ssh command line, not just that
+            # *some* connection to this host succeeds.
+            echo "Welcome to the fake host."
+            while IFS= read -r line; do
+                echo "$line"
+            done
+            exit 0
+            ;;
+        *@requireuser|requireuser)
+            echo "Permission denied (publickey,password)." >&2
+            exit 255
+            ;;
         *@succeed|succeed)
             echo "Welcome to the fake host."
             # Stay alive echoing stdin back (simulates an interactive

tests/test_ssh_session_backend.cpp

@@ -21,6 +21,13 @@ Profile makeProfile(const QString& fixtureHost)
     return profile;
 }
 
+Profile makeBlankUsernameProfile(const QString& fixtureHost)
+{
+    Profile profile = makeProfile(fixtureHost);
+    profile.username.clear();
+    return profile;
+}
+
 SessionConnectOptions makeOptions()
 {
     SessionConnectOptions options;
@@ -50,10 +57,12 @@ private slots:
     void connectionRefusedReachesFailedState();
     void sendInputEchoesThroughOutputReceived();
     void reconnectRestartsAndReachesConnectedAgain();
+    void connectOptionsUsernameReachesProcessWhenProfileUsernameIsBlank();
 
 private:
     QString fixturePath() const;
     void createBackend(const QString& fixtureHost);
+    void createBackend(const Profile& profile);
 
     std::unique_ptr<SshSessionBackend> m_backend;
     SessionState m_lastState = SessionState::Disconnected;
@@ -69,8 +78,12 @@ QString TestSshSessionBackend::fixturePath() const
 
 void TestSshSessionBackend::createBackend(const QString& fixtureHost)
 {
-    m_backend =
-        std::make_unique<SshSessionBackend>(makeProfile(fixtureHost), fixturePath(), nullptr);
+    createBackend(makeProfile(fixtureHost));
+}
+
+void TestSshSessionBackend::createBackend(const Profile& profile)
+{
+    m_backend = std::make_unique<SshSessionBackend>(profile, fixturePath(), nullptr);
     connect(m_backend.get(),
             &SessionBackend::stateChanged,
             this,
@@ -232,5 +245,24 @@ void TestSshSessionBackend::reconnectRestartsAndReachesConnectedAgain()
     QTRY_COMPARE(m_lastState, SessionState::Connected);
 }
 
+void TestSshSessionBackend::connectOptionsUsernameReachesProcessWhenProfileUsernameIsBlank()
+{
+    // Regression test for a bug where a username entered at the
+    // connect-time prompt (SessionTab::requestConnectOptions(), for a
+    // profile with no saved username -- issue #21) never actually reached
+    // the ssh process: SshSessionBackend built its target purely from
+    // profile().username, which is a separate copy captured when the
+    // backend was constructed and never sees SessionTab's later edit.
+    // fixtures/fake_ssh.sh's "requireuser" host only accepts the exact
+    // target "prompted-user@requireuser", so this fails unless
+    // SessionConnectOptions::username is actually used.
+    createBackend(makeBlankUsernameProfile(QStringLiteral("requireuser")));
+
+    SessionConnectOptions options = makeOptions();
+    options.username = QStringLiteral("prompted-user");
+    m_backend->connectSession(options);
+    QTRY_COMPARE(m_lastState, SessionState::Connected);
+}
+
 QTEST_GUILESS_MAIN(TestSshSessionBackend)
 #include "test_ssh_session_backend.moc"