[3.12] gh-64662: Fix virtual table support in sqlite3.Connection.iterdump (#108340) (#108563)

* [3.12] gh-64662: Add virtual table support to sqlite3.Connection.iterdump (#108340)

(cherry picked from commit d0160c7c22c8dff0a61c49b5304244df6e36465e)

Co-authored-by: Aviv Palivoda <palaviv@gmail.com>

* The _quote_value helper is not part of 3.12; spell out the replacement

* With quotes

* Ok, let's use explicit quoting

---------

Co-authored-by: Aviv Palivoda <palaviv@gmail.com>

1 files changed, 13 insertions, 7 deletions

diff --git a/Lib/sqlite3/dump.py b/Lib/sqlite3/dump.py
index 07b9da1..1cf8759 100644
--- a/Lib/sqlite3/dump.py
+++ b/Lib/sqlite3/dump.py
@@ -16,6 +16,7 @@ def _iterdump(connection):
     directly but instead called from the Connection method, iterdump().
     """
 
+    writeable_schema = False
     cu = connection.cursor()
     yield('BEGIN TRANSACTION;')
 
@@ -42,13 +43,15 @@ def _iterdump(connection):
             yield('ANALYZE "sqlite_master";')
         elif table_name.startswith('sqlite_'):
             continue
-        # NOTE: Virtual table support not implemented
-        #elif sql.startswith('CREATE VIRTUAL TABLE'):
-        #    qtable = table_name.replace("'", "''")
-        #    yield("INSERT INTO sqlite_master(type,name,tbl_name,rootpage,sql)"\
-        #        "VALUES('table','{0}','{0}',0,'{1}');".format(
-        #        qtable,
-        #        sql.replace("''")))
+        elif sql.startswith('CREATE VIRTUAL TABLE'):
+            if not writeable_schema:
+                writeable_schema = True
+                yield('PRAGMA writable_schema=ON;')
+            yield("INSERT INTO sqlite_master(type,name,tbl_name,rootpage,sql)"
+                  "VALUES('table','{0}','{0}',0,'{1}');".format(
+                      table_name.replace("'", "''"),
+                      sql.replace("'", "''"),
+                  ))
         else:
             yield('{0};'.format(sql))
 
@@ -74,6 +77,9 @@ def _iterdump(connection):
     for name, type, sql in schema_res.fetchall():
         yield('{0};'.format(sql))
 
+    if writeable_schema:
+        yield('PRAGMA writable_schema=OFF;')
+
     # gh-79009: Yield statements concerning the sqlite_sequence table at the
     # end of the transaction.
     for row in sqlite_sequence: