update url bar on url modifications

this properly tracks e.g. saveAs or
the "we switch to new file in the current one"

kate/kateurlbar.cpp

@@ -439,22 +439,40 @@ KateUrlBar::KateUrlBar(KateViewSpace *parent)
 void KateUrlBar::onViewChanged(KTextEditor::View *v)
 {
     if (!v) {
+        updateForDocument(nullptr);
         hide();
         return;
     }
 
+    updateForDocument(v->document());
+}
+
+void KateUrlBar::updateForDocument(KTextEditor::Document *doc)
+{
+    // always disconnect and perhaps set nullptr doc
+    if (m_currentDoc) {
+        disconnect(m_currentDoc, &KTextEditor::Document::documentUrlChanged, this, &KateUrlBar::updateForDocument);
+    }
+    m_currentDoc = doc;
+    if (!doc) {
+        return;
+    }
+
+    // we want to watch for url changed
+    connect(m_currentDoc, &KTextEditor::Document::documentUrlChanged, this, &KateUrlBar::updateForDocument);
+
     auto *vm = static_cast<KateViewSpace *>(parentWidget())->viewManger();
     if (vm && !vm->showUrlNavBar()) {
         return;
     }
 
-    const auto url = v->document()->url();
+    const auto url = doc->url();
     if (url.isEmpty() || !url.isLocalFile()) {
         hide();
         return;
     }
 
-    m_breadCrumbView->setUrl(v->document()->url());
+    m_breadCrumbView->setUrl(url);
 
     if (isHidden())
         show();

kate/kateurlbar.h

@@ -6,7 +6,9 @@
 #define KATE_URL_BAR_H
 
 #include "kateviewspace.h"
+
 #include <QFrame>
+#include <QPointer>
 
 class KateUrlBar : public QWidget
 {
@@ -19,7 +21,12 @@ Q_SIGNALS:
 
 private:
     void onViewChanged(KTextEditor::View *v);
+    void updateForDocument(KTextEditor::Document *doc);
     class BreadCrumbView *m_breadCrumbView;
+
+    // document for which the url bar is currently active
+    // might be nullptr
+    QPointer<KTextEditor::Document> m_currentDoc;
 };
 
 #endif