E-book viewer: Fix back button not working after jumping to a bookmark. Fixes #1931599 [[Enhancement] E-book viewer: clicking on bookmarks should create jump positions](https://bugs.launchpad.net/calibre/+bug/1931599)

src/calibre/gui2/viewer/ui.py

@@ -366,11 +366,11 @@ class EbookViewer(MainWindow):
         # annotations will be saved in book file on exit
         self.save_annotations(in_book_file=False)
 
-    def goto_cfi(self, cfi):
-        self.web_view.goto_cfi(cfi)
+    def goto_cfi(self, cfi, add_to_history=False):
+        self.web_view.goto_cfi(cfi, add_to_history=add_to_history)
 
     def bookmark_activated(self, cfi):
-        self.goto_cfi(cfi)
+        self.goto_cfi(cfi, add_to_history=True)
 
     def view_image(self, name):
         path = get_path_for_name(name)

src/calibre/gui2/viewer/web_view.py

@@ -649,8 +649,8 @@ class WebView(RestartingWebEngineView):
     def goto_toc_node(self, node_id):
         self.execute_when_ready('goto_toc_node', node_id)
 
-    def goto_cfi(self, cfi):
-        self.execute_when_ready('goto_cfi', cfi)
+    def goto_cfi(self, cfi, add_to_history=False):
+        self.execute_when_ready('goto_cfi', cfi, bool(add_to_history))
 
     def notify_full_screen_state_change(self, in_fullscreen_mode):
         self.execute_when_ready('full_screen_state_changed', in_fullscreen_mode)

src/pyj/read_book/bookmarks.pyj

@@ -12,7 +12,7 @@ from widgets import create_button
 
 
 def goto_cfi(cfi, view):
-    view.goto_cfi(cfi)
+    view.goto_cfi(cfi, True)
 
 
 def remove_bookmark(annotations_manager, title, list_dom_node):

src/pyj/viewer-main.pyj

@@ -234,8 +234,8 @@ def goto_toc_node(node_id):
 
 
 @from_python
-def goto_cfi(cfi):
-    view.goto_cfi(cfi)
+def goto_cfi(cfi, add_to_history):
+    view.goto_cfi(cfi, v'!!add_to_history')
 
 
 @from_python