From c9665822657f395594b60d830ac2dccc8e0ff130 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Fri, 22 Sep 2023 19:38:27 +0530
Subject: [PATCH] HTMLDisplay: Add resources to the document so they are not
 repeatedly loaded

---
 src/calibre/gui2/widgets2.py | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/src/calibre/gui2/widgets2.py b/src/calibre/gui2/widgets2.py
index 3738df1f04..9e01793228 100644
--- a/src/calibre/gui2/widgets2.py
+++ b/src/calibre/gui2/widgets2.py
@@ -580,16 +580,22 @@ class HTMLDisplay(QTextBrowser):
                     data = f.read()
             except OSError:
                 if path.rpartition('.')[-1].lower() in {'jpg', 'jpeg', 'gif', 'png', 'bmp', 'webp'}:
-                    return QByteArray(bytearray.fromhex(
+                    r = QByteArray(bytearray.fromhex(
                         '89504e470d0a1a0a0000000d49484452'
                         '000000010000000108060000001f15c4'
                         '890000000a49444154789c6300010000'
                         '0500010d0a2db40000000049454e44ae'
                         '426082'))
+                    self.document().addResource(rtype, qurl, r)
+                    return r
             else:
-                return QByteArray(data)
+                r = QByteArray(data)
+                self.document().addResource(rtype, qurl, r)
+                return r
         elif qurl.scheme() == 'calibre-icon':
-            return QIcon.icon_as_png(qurl.path().lstrip('/'), as_bytearray=True)
+            r = QIcon.icon_as_png(qurl.path().lstrip('/'), as_bytearray=True)
+            self.document().addResource(rtype, qurl, r)
+            return r
         elif self.notes_resource_scheme and qurl.scheme() == self.notes_resource_scheme and int(rtype) == int(QTextDocument.ResourceType.ImageResource):
             from calibre.gui2.ui import get_gui
             gui = get_gui()
@@ -597,7 +603,9 @@ class HTMLDisplay(QTextBrowser):
                 db = gui.current_db.new_api
                 resource = db.get_notes_resource(f'{qurl.host()}:{qurl.path()[1:]}')
                 if resource is not None:
-                    return QByteArray(resource['data'])
+                    r = QByteArray(resource['data'])
+                    self.document().addResource(rtype, qurl, r)
+                    return r
         else:
             return QTextBrowser.loadResource(self, rtype, qurl)