Check for valid _foregroundProcessInfo to prevent crash

Summary:
In Session::getUrl() check that _foregroundProcessInfo is valid before
tyring to access its members.

I couldn't reproduce the crash from the BR, but it is logical to call
isValid() before accessing any ProcessInfo object members.

BUG: 391447

Reviewers: #konsole, hindenburg

Reviewed By: #konsole, hindenburg

Subscribers: #konsole

Tags: #konsole

Differential Revision: https://phabricator.kde.org/D12175

src/Session.cpp

@@ -1157,7 +1157,7 @@ QUrl Session::getUrl()
         bool ok = false;
 
         // check if foreground process is bookmark-able
-        if (isForegroundProcessActive()) {
+        if (isForegroundProcessActive() && _foregroundProcessInfo->isValid()) {
             // for remote connections, save the user and host
             // bright ideas to get the directory at the other end are welcome :)
             if (_foregroundProcessInfo->name(&ok) == QLatin1String("ssh") && ok) {