From a8483d86265de1f8f599a09457dfb25bd94f8118 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Mon, 20 Jun 2022 11:29:10 +0530
Subject: [PATCH] Allow loading of calibre sqlite extension when connecting via
 python sqlite3 module as well

---
 src/calibre/constants.py            | 9 +++++++++
 src/calibre/db/sqlite_extension.cpp | 5 +++++
 src/calibre/library/sqlite.py       | 3 ++-
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/calibre/constants.py b/src/calibre/constants.py
index 3a4cd1fecb..1069d7a328 100644
--- a/src/calibre/constants.py
+++ b/src/calibre/constants.py
@@ -344,6 +344,15 @@ class Plugins(collections.abc.Mapping):
         finally:
             conn.enableloadextension(False)
 
+    def load_sqlite3_extension(self, conn, name):
+        conn.enable_load_extension(True)
+        try:
+            ext = 'pyd' if iswindows else 'so'
+            path = os.path.join(plugins_loc, f'{name}.{ext}')
+            conn.load_extension(path)
+        finally:
+            conn.enable_load_extension(False)
+
 
 plugins = None
 if plugins is None:
diff --git a/src/calibre/db/sqlite_extension.cpp b/src/calibre/db/sqlite_extension.cpp
index a6b3bdf4a0..617c20a5c2 100644
--- a/src/calibre/db/sqlite_extension.cpp
+++ b/src/calibre/db/sqlite_extension.cpp
@@ -448,6 +448,11 @@ calibre_sqlite_extension_init(sqlite3 *db, char **pzErrMsg, const sqlite3_api_ro
     fts5api->xCreateTokenizer(fts5api, "porter", reinterpret_cast<void *>(fts5api), &tok2, NULL);
     return SQLITE_OK;
 }
+
+MYEXPORT int
+sqlite3_sqliteextension_init(sqlite3 *db, char **pzErrMsg, const sqlite3_api_routines *pApi){
+    return calibre_sqlite_extension_init(db, pzErrMsg, pApi);
+}
 }
 
 static PyObject*
diff --git a/src/calibre/library/sqlite.py b/src/calibre/library/sqlite.py
index 8c7139af1b..593ddb6fa5 100644
--- a/src/calibre/library/sqlite.py
+++ b/src/calibre/library/sqlite.py
@@ -17,7 +17,7 @@ from functools import partial
 from calibre.ebooks.metadata import title_sort, author_to_author_sort
 from calibre.utils.date import parse_date, isoformat, local_tz, UNDEFINED_DATE
 from calibre import isbytestring, force_unicode
-from calibre.constants import iswindows, DEBUG, plugins_loc
+from calibre.constants import iswindows, DEBUG, plugins_loc, plugins
 from calibre.utils.icu import sort_key
 from calibre_extensions import speedup as _c_speedup
 from calibre import prints
@@ -270,6 +270,7 @@ def do_connect(path, row_factory=None):
     # Dummy functions for dynamically created filters
     conn.create_function('books_list_filter', 1, lambda x: 1)
     conn.create_collation(native_string_type('icucollate'), icu_collator)
+    plugins.load_sqlite3_extension(conn, 'sqlite_extension')
     return conn