Allow removing individual books from the FTS index if they are somehow missing from the main db

src/calibre/db/backend.py

@@ -979,6 +979,9 @@ class DB:
         if self.fts is not None:
             return self.fts.commit_result(book_id, fmt, fmt_size, fmt_hash, text, err_msg)
 
+    def fts_unindex(self, book_id, fmt=None):
+        self.fts.unindex(book_id, fmt=fmt)
+
     def fts_search(self,
         fts_engine_query, use_stemming, highlight_start, highlight_end, snippet_size, restrict_to_book_ids, return_text,
     ):

src/calibre/db/cache.py

@@ -475,6 +475,10 @@ class Cache:
             self.fts_job_queue = Queue()
         return fts
 
+    @write_api
+    def fts_unindex(self, book_id, fmt=None):
+        self.backend.fts_unindex(book_id, fmt=fmt)
+
     @staticmethod
     def dispatch_fts_jobs(queue, dbref):
         from .fts.text import is_fmt_ok

src/calibre/db/fts/connect.py

@@ -87,6 +87,13 @@ class FTS:
         conn = self.get_connection()
         conn.execute('DELETE FROM fts_db.dirtied_formats WHERE book=? AND format=?', (book_id, fmt.upper()))
 
+    def unindex(self, book_id, fmt=None):
+        conn = self.get_connection()
+        if fmt is None:
+            conn.execute('DELETE FROM books_text WHERE book=?', (book_id,))
+        else:
+            conn.execute('DELETE FROM books_text WHERE book=? AND format=?', (book_id, fmt.upper()))
+
     def add_text(self, book_id, fmt, text, text_hash='', fmt_size=0, fmt_hash='', err_msg=''):
         conn = self.get_connection()
         ts = (utcnow() - EPOCH).total_seconds()

src/calibre/gui2/fts/search.py

@@ -237,6 +237,17 @@ class ResultsModel(QAbstractItemModel):
         self.current_thread.start()
         return True
 
+    def remove_book(self, book_id):
+        idx = self.result_map.get(book_id)
+        if idx is not None:
+            self.beginRemoveRows(ROOT, idx, idx)
+            del self.results[idx]
+            del self.result_map[book_id]
+            self.endRemoveRows()
+            self.matches_found.emit(len(self.results))
+            return True
+        return False
+
     def search_text_in_thread(self, query_id, abort, *a, **kw):
         db = get_db()
         generator = db.fts_search(*a, **kw, result_type=lambda x: x)
@@ -506,6 +517,7 @@ class SearchInputPanel(QWidget):
 class ResultDetails(QWidget):
 
     show_in_viewer = pyqtSignal(int, int, str)
+    remove_book_from_results = pyqtSignal(int)
 
     def __init__(self, parent=None):
         super().__init__(parent)
@@ -533,6 +545,10 @@ class ResultDetails(QWidget):
                 mark_books(self.current_book_id)
             elif url.host() == 'jump':
                 jump_to_book(self.current_book_id)
+            elif url.host() == 'unindex':
+                db = get_db()
+                db.fts_unindex(self.current_book_id)
+                self.remove_book_from_results.emit(self.current_book_id)
 
     def results_anchor_clicked(self, url):
         if self.current_book_id > 0 and url.scheme() == 'book':
@@ -601,6 +617,10 @@ class ResultDetails(QWidget):
             _('Mark'), '<p>' + _(
                 'Put a pin on this book in the calibre library, for future reference.'
                 ' You can search for marked books using the search term: {0}').format('<p>marked:true'))
+        if not get_db().has_id(results.book_id):
+            text += '<p><a href="calibre://unindex" title="{1}"><img valign="bottom" src="calibre-icon:///trash.png" width=16 height=16>\xa0{0}</a>'.format(
+                _('Remove from index'), _('This book has been deleted from the library but is still present in the'
+                                          ' full text search index. Remove it.'))
         self.book_info.setHtml(text)
 
     def render_results(self, results, individual_match=None):
@@ -643,6 +663,7 @@ class ResultDetails(QWidget):
 class DetailsPanel(QStackedWidget):
 
     show_in_viewer = pyqtSignal(int, int, str)
+    remove_book_from_results = pyqtSignal(int)
 
     def __init__(self, parent=None):
         super().__init__(parent)
@@ -683,6 +704,7 @@ p { margin: 0; }
 
         self.result_details = rd = ResultDetails(self)
         rd.show_in_viewer.connect(self.show_in_viewer)
+        rd.remove_book_from_results.connect(self.remove_book_from_results)
         self.addWidget(rd)
 
     def sizeHint(self):
@@ -745,6 +767,7 @@ class ResultsPanel(QWidget):
 
         self.details = d = DetailsPanel(self)
         d.show_in_viewer.connect(self.show_in_viewer)
+        d.remove_book_from_results.connect(self.remove_book_from_results)
         rv.current_changed.connect(d.show_result)
         rv.search_started.connect(d.clear)
         rv.result_with_context_found.connect(d.result_with_context_found)
@@ -753,6 +776,9 @@ class ResultsPanel(QWidget):
         if st is not None:
             s.restoreState(st)
 
+    def remove_book_from_results(self, book_id):
+        self.results_view.m.remove_book(book_id)
+
     def show_in_viewer(self, book_id, result_num, fmt):
         r = self.results_view.m.get_result(book_id, result_num)
         text = r['text'].strip('…').replace('\x1d', '').replace('\xa0', ' ')