Also dynamically adjust mark text action's text when showing context menu

src/calibre/gui2/tweak_book/__init__.py

@@ -122,3 +122,10 @@ def verify_link(url, name=None):
     if url.partition(':')[0] in {'http', 'https', 'mailto'}:
         return True
     return False
+
+def update_mark_text_action(ed=None):
+    has_mark = False
+    if ed is not None and ed.has_line_numbers:
+        has_mark = bool(ed.selected_text) or not ed.has_marked_text
+    ac = actions['mark-selected-text']
+    ac.setText(ac.default_text if has_mark else _('Unmark marked text'))

src/calibre/gui2/tweak_book/editor/widget.py

@@ -16,7 +16,9 @@ from PyQt5.Qt import (
 from calibre import prints
 from calibre.constants import DEBUG
 from calibre.ebooks.chardet import replace_encoding_declarations
-from calibre.gui2.tweak_book import actions, current_container, tprefs, dictionaries, editor_toolbar_actions, editor_name, editors
+from calibre.gui2.tweak_book import (
+    actions, current_container, tprefs, dictionaries, editor_toolbar_actions,
+    editor_name, editors, update_mark_text_action)
 from calibre.gui2 import error_dialog, open_url, workaround_broken_under_mouse
 from calibre.gui2.tweak_book.editor import SPELL_PROPERTY, LINK_PROPERTY, TAG_NAME_PROPERTY, CSS_PROPERTY
 from calibre.gui2.tweak_book.editor.help import help_url
@@ -503,6 +505,8 @@ class Editor(QMainWindow):
                 a(ac)
         m.addSeparator()
         m.addAction(_('&Select all'), self.editor.select_all)
+        if self.selected_text or self.has_marked_text:
+            update_mark_text_action(self)
             m.addAction(actions['mark-selected-text'])
         if self.syntax != 'css' and actions['editor-cut'].isEnabled():
             cm = QMenu(_('Change &case'), m)

src/calibre/gui2/tweak_book/ui.py

@@ -22,7 +22,8 @@ from calibre.gui2 import elided_text, open_url
 from calibre.gui2.keyboard import Manager as KeyboardManager
 from calibre.gui2.main_window import MainWindow
 from calibre.gui2.throbber import ThrobbingButton, create_donate_widget
-from calibre.gui2.tweak_book import current_container, tprefs, actions, capitalize, toolbar_actions, editors
+from calibre.gui2.tweak_book import (
+    current_container, tprefs, actions, capitalize, toolbar_actions, editors, update_mark_text_action)
 from calibre.gui2.tweak_book.file_list import FileListWidget
 from calibre.gui2.tweak_book.job import BlockingJob
 from calibre.gui2.tweak_book.boss import Boss
@@ -415,7 +416,7 @@ class Main(MainWindow):
                                    'count', keys=('Ctrl+N'), description=_('Count number of matches'))
         self.action_mark = reg(None, _('&Mark selected text'), self.boss.mark_selected_text, 'mark-selected-text', ('Ctrl+Shift+M',),
                                _('Mark selected text or unmark already marked text'))
-        self.mark_text_string = self.action_mark.text()
+        self.action_mark.default_text = self.action_mark.text()
         self.action_go_to_line = reg(None, _('Go to &line'), self.boss.go_to_line_number, 'go-to-line-number', ('Ctrl+.',), _('Go to line number'))
         self.action_saved_searches = treg('folder_saved_search.png', _('Sa&ved searches'),
                                           self.boss.saved_searches, 'saved-searches', (), _('Show the saved searches dialog'))
@@ -562,9 +563,7 @@ class Main(MainWindow):
 
     def search_menu_about_to_show(self):
         ed = self.central.current_editor
-        if ed is not None and ed.has_line_numbers:
+        update_mark_text_action(ed)
-            mark = bool(ed.selected_text) or not ed.has_marked_text
-            self.action_mark.setText(self.mark_text_string if mark else _('Unmark marked text'))
 
     def update_recent_books(self):
         m = self.recent_books_menu