From 2571aa6b0323a12755a2914f3bc36acde9648b88 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 31 Aug 2021 22:43:54 +0200
Subject: [PATCH 01/18] Clean up connection init, WIP

---
 Modules/_sqlite/connection.c | 113 ++++++++++++++++++++---------------
 1 file changed, 65 insertions(+), 48 deletions(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index bf803370c05719..d73aef3d690e51 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -58,15 +58,17 @@ static void _pysqlite_drop_unused_cursor_references(pysqlite_Connection* self);
 static void free_callback_context(callback_context *ctx);
 static void set_callback_context(callback_context **ctx_pp,
                                  callback_context *ctx);
+static void connection_close(pysqlite_Connection *self);
 
 static PyObject *
-new_statement_cache(pysqlite_Connection *self, int maxsize)
+new_statement_cache(pysqlite_Connection *self, pysqlite_state *state,
+                    int maxsize)
 {
     PyObject *args[] = { NULL, PyLong_FromLong(maxsize), };
     if (args[1] == NULL) {
         return NULL;
     }
-    PyObject *lru_cache = self->state->lru_cache;
+    PyObject *lru_cache = state->lru_cache;
     size_t nargsf = 1 | PY_VECTORCALL_ARGUMENTS_OFFSET;
     PyObject *inner = PyObject_Vectorcall(lru_cache, args + 1, nargsf, NULL);
     Py_DECREF(args[1]);
@@ -102,76 +104,63 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
                               int cached_statements, int uri)
 /*[clinic end generated code: output=dc19df1c0e2b7b77 input=aa1f21bf12fe907a]*/
 {
-    int rc;
-
     if (PySys_Audit("sqlite3.connect", "O", database_obj) < 0) {
+        Py_DECREF(database_obj);  // needed bco. the AC FSConverter
         return -1;
     }
 
-    pysqlite_state *state = pysqlite_get_state_by_type(Py_TYPE(self));
-    self->state = state;
+    if (self->initialized) {
+        connection_close(self);
+        self->initialized = 0;
+    }
 
+    // Create and configure SQLite database object
+    sqlite3 *db;
     const char *database = PyBytes_AsString(database_obj);
-
-    self->begin_statement = NULL;
-
-    Py_CLEAR(self->statement_cache);
-    Py_CLEAR(self->cursors);
-
-    Py_INCREF(Py_None);
-    Py_XSETREF(self->row_factory, Py_None);
-
-    Py_INCREF(&PyUnicode_Type);
-    Py_XSETREF(self->text_factory, (PyObject*)&PyUnicode_Type);
-
+    int rc;
     Py_BEGIN_ALLOW_THREADS
-    rc = sqlite3_open_v2(database, &self->db,
+    rc = sqlite3_open_v2(database, &db,
                          SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE |
                          (uri ? SQLITE_OPEN_URI : 0), NULL);
+    if (rc == SQLITE_OK) {
+        (void)sqlite3_busy_timeout(db, (int)(timeout*1000));
+    }
     Py_END_ALLOW_THREADS
 
     Py_DECREF(database_obj);  // needed bco. the AC FSConverter
 
+    pysqlite_state *state = pysqlite_get_state_by_type(Py_TYPE(self));
     if (rc != SQLITE_OK) {
-        _pysqlite_seterror(state, self->db);
+        _pysqlite_seterror(state, db);
         return -1;
     }
 
-    if (!isolation_level) {
-        isolation_level = PyUnicode_FromString("");
-        if (!isolation_level) {
-            return -1;
-        }
-    } else {
-        Py_INCREF(isolation_level);
-    }
-    Py_CLEAR(self->isolation_level);
-    if (pysqlite_connection_set_isolation_level(self, isolation_level, NULL) != 0) {
-        Py_DECREF(isolation_level);
-        return -1;
-    }
-    Py_DECREF(isolation_level);
-
-    self->statement_cache = new_statement_cache(self, cached_statements);
-    if (self->statement_cache == NULL) {
-        return -1;
-    }
-    if (PyErr_Occurred()) {
+    // Create cursor weak ref list and statement cache
+    PyObject *cursors = PyList_New(0);
+    if (cursors == NULL) {
         return -1;
     }
 
-    self->created_cursors = 0;
-
-    /* Create list of weak references to cursors */
-    self->cursors = PyList_New(0);
-    if (self->cursors == NULL) {
+    PyObject *cache = new_statement_cache(self, state, cached_statements);
+    if (cache == NULL) {
+        Py_DECREF(cursors);
         return -1;
     }
 
+    // Init connection state members
+    self->db = db;
+    self->state = state;
     self->detect_types = detect_types;
-    (void)sqlite3_busy_timeout(self->db, (int)(timeout*1000));
-    self->thread_ident = PyThread_get_thread_ident();
+    self->begin_statement = NULL;
     self->check_same_thread = check_same_thread;
+    self->thread_ident = PyThread_get_thread_ident();
+    self->created_cursors = 0;
+
+    Py_CLEAR(self->isolation_level);
+    Py_XSETREF(self->statement_cache, cache);
+    Py_XSETREF(self->cursors, cursors);
+    Py_XSETREF(self->row_factory, Py_NewRef(Py_None));
+    Py_XSETREF(self->text_factory, Py_NewRef(&PyUnicode_Type));
 
     set_callback_context(&self->trace_ctx, NULL);
     set_callback_context(&self->progress_ctx, NULL);
@@ -188,12 +177,27 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     self->ProgrammingError      = state->ProgrammingError;
     self->NotSupportedError     = state->NotSupportedError;
 
+    // Set isolation level at last, since it may trigger a COMMIT
+    if (isolation_level == NULL) {
+        isolation_level = PyUnicode_FromString("");
+        if (isolation_level == NULL) {
+            return -1;
+        }
+    }
+    else {
+        Py_INCREF(isolation_level);
+    }
+    rc = pysqlite_connection_set_isolation_level(self, isolation_level, NULL);
+    Py_DECREF(isolation_level);
+    if (rc < 0) {
+        return -1;
+    }
+
     if (PySys_Audit("sqlite3.connect/handle", "O", self) < 0) {
         return -1;
     }
 
     self->initialized = 1;
-
     return 0;
 }
 
@@ -264,10 +268,23 @@ connection_clear(pysqlite_Connection *self)
     return 0;
 }
 
+static void
+clear_sqlite_callbacks(pysqlite_Connection *self)
+{
+    (void)sqlite3_set_authorizer(self->db, NULL, NULL);
+    sqlite3_progress_handler(self->db, 0, NULL, NULL);
+#ifdef HAVE_TRACE_V2
+    sqlite3_trace_v2(self->db, SQLITE_TRACE_STMT, NULL, NULL);
+#else
+    sqlite3_trace(self->db, NULL, NULL);
+#endif
+}
+
 static void
 connection_close(pysqlite_Connection *self)
 {
     if (self->db) {
+        clear_sqlite_callbacks(self);
         int rc = sqlite3_close_v2(self->db);
         assert(rc == SQLITE_OK), (void)rc;
         self->db = NULL;

From 101253ab39cb71b6e08e7c72b7276039f638f2c6 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 21:58:42 +0200
Subject: [PATCH 02/18] Use AC to simplify reference handling in __init__

---
 Modules/_sqlite/clinic/connection.c.h | 13 ++++---
 Modules/_sqlite/connection.c          | 49 ++++++++++++++++++++++-----
 2 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/Modules/_sqlite/clinic/connection.c.h b/Modules/_sqlite/clinic/connection.c.h
index 315d163dde668f..bf5a58d7756c9e 100644
--- a/Modules/_sqlite/clinic/connection.c.h
+++ b/Modules/_sqlite/clinic/connection.c.h
@@ -4,7 +4,7 @@ preserve
 
 static int
 pysqlite_connection_init_impl(pysqlite_Connection *self,
-                              PyObject *database_obj, double timeout,
+                              const char *database, double timeout,
                               int detect_types, PyObject *isolation_level,
                               int check_same_thread, PyObject *factory,
                               int cached_statements, int uri);
@@ -19,7 +19,7 @@ pysqlite_connection_init(PyObject *self, PyObject *args, PyObject *kwargs)
     PyObject * const *fastargs;
     Py_ssize_t nargs = PyTuple_GET_SIZE(args);
     Py_ssize_t noptargs = nargs + (kwargs ? PyDict_GET_SIZE(kwargs) : 0) - 1;
-    PyObject *database_obj;
+    const char *database = NULL;
     double timeout = 5.0;
     int detect_types = 0;
     PyObject *isolation_level = NULL;
@@ -32,7 +32,7 @@ pysqlite_connection_init(PyObject *self, PyObject *args, PyObject *kwargs)
     if (!fastargs) {
         goto exit;
     }
-    if (!PyUnicode_FSConverter(fastargs[0], &database_obj)) {
+    if (!clinic_fsconverter(fastargs[0], &database)) {
         goto exit;
     }
     if (!noptargs) {
@@ -97,9 +97,12 @@ pysqlite_connection_init(PyObject *self, PyObject *args, PyObject *kwargs)
         goto exit;
     }
 skip_optional_pos:
-    return_value = pysqlite_connection_init_impl((pysqlite_Connection *)self, database_obj, timeout, detect_types, isolation_level, check_same_thread, factory, cached_statements, uri);
+    return_value = pysqlite_connection_init_impl((pysqlite_Connection *)self, database, timeout, detect_types, isolation_level, check_same_thread, factory, cached_statements, uri);
 
 exit:
+    /* Cleanup for database */
+    PyMem_Free((void *)database);
+
     return return_value;
 }
 
@@ -816,4 +819,4 @@ pysqlite_connection_exit(pysqlite_Connection *self, PyObject *const *args, Py_ss
 #ifndef PYSQLITE_CONNECTION_LOAD_EXTENSION_METHODDEF
     #define PYSQLITE_CONNECTION_LOAD_EXTENSION_METHODDEF
 #endif /* !defined(PYSQLITE_CONNECTION_LOAD_EXTENSION_METHODDEF) */
-/*[clinic end generated code: output=9c0dfc6c1ebf9039 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=5b7268875f33c016 input=a9049054013a1b77]*/
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index d73aef3d690e51..8e1ebb8d531226 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -33,6 +33,32 @@
 #define HAVE_TRACE_V2
 #endif
 
+static int
+clinic_fsconverter(PyObject *pathlike, const char **result)
+{
+    PyObject *bytes = NULL;
+    Py_ssize_t len;
+    char *str;
+
+    if (!PyUnicode_FSConverter(pathlike, &bytes)) {
+        goto error;
+    }
+    else if (PyBytes_AsStringAndSize(bytes, &str, &len) < 0) {
+        goto error;
+    }
+    else if ((*result = PyMem_Malloc(len))) {
+        goto error;
+    }
+
+    memcpy((void *)(*result), str, len);
+    Py_DECREF(bytes);
+    return 1;
+
+error:
+    Py_XDECREF(bytes);
+    return 0;
+}
+
 #define clinic_state() (pysqlite_get_state(NULL))
 #include "clinic/connection.c.h"
 #undef clinic_state
@@ -83,10 +109,21 @@ new_statement_cache(pysqlite_Connection *self, pysqlite_state *state,
     return res;
 }
 
+/*[python input]
+class FSConverter_converter(CConverter):
+    type = "const char *"
+    converter = "clinic_fsconverter"
+    def converter_init(self):
+        self.c_default = "NULL"
+    def cleanup(self):
+        return f"PyMem_Free((void *){self.name});\n"
+[python start generated code]*/
+/*[python end generated code: output=da39a3ee5e6b4b0d input=7b3be538bc4058c0]*/
+
 /*[clinic input]
 _sqlite3.Connection.__init__ as pysqlite_connection_init
 
-    database as database_obj: object(converter='PyUnicode_FSConverter')
+    database: FSConverter
     timeout: double = 5.0
     detect_types: int = 0
     isolation_level: object = NULL
@@ -98,14 +135,13 @@ _sqlite3.Connection.__init__ as pysqlite_connection_init
 
 static int
 pysqlite_connection_init_impl(pysqlite_Connection *self,
-                              PyObject *database_obj, double timeout,
+                              const char *database, double timeout,
                               int detect_types, PyObject *isolation_level,
                               int check_same_thread, PyObject *factory,
                               int cached_statements, int uri)
-/*[clinic end generated code: output=dc19df1c0e2b7b77 input=aa1f21bf12fe907a]*/
+/*[clinic end generated code: output=bc39e55eb0b68783 input=f8d1f7efc0d84104]*/
 {
-    if (PySys_Audit("sqlite3.connect", "O", database_obj) < 0) {
-        Py_DECREF(database_obj);  // needed bco. the AC FSConverter
+    if (PySys_Audit("sqlite3.connect", "s", database) < 0) {
         return -1;
     }
 
@@ -116,7 +152,6 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
 
     // Create and configure SQLite database object
     sqlite3 *db;
-    const char *database = PyBytes_AsString(database_obj);
     int rc;
     Py_BEGIN_ALLOW_THREADS
     rc = sqlite3_open_v2(database, &db,
@@ -127,8 +162,6 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     }
     Py_END_ALLOW_THREADS
 
-    Py_DECREF(database_obj);  // needed bco. the AC FSConverter
-
     pysqlite_state *state = pysqlite_get_state_by_type(Py_TYPE(self));
     if (rc != SQLITE_OK) {
         _pysqlite_seterror(state, db);

From c3efc544427722dbfce6d7068d21707c2579e9fe Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 22:08:09 +0200
Subject: [PATCH 03/18] Clear object if reinitialising

---
 Modules/_sqlite/connection.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 8e1ebb8d531226..4ced9f5c783196 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -147,6 +147,8 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
 
     if (self->initialized) {
         connection_close(self);
+        PyTypeObject *tp = Py_TYPE(self);
+        tp->tp_clear((PyObject *)self);
         self->initialized = 0;
     }
 
@@ -184,20 +186,18 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     self->db = db;
     self->state = state;
     self->detect_types = detect_types;
+    self->isolation_level = NULL;
     self->begin_statement = NULL;
     self->check_same_thread = check_same_thread;
     self->thread_ident = PyThread_get_thread_ident();
+    self->statement_cache = cache;
+    self->cursors = cursors;
     self->created_cursors = 0;
-
-    Py_CLEAR(self->isolation_level);
-    Py_XSETREF(self->statement_cache, cache);
-    Py_XSETREF(self->cursors, cursors);
-    Py_XSETREF(self->row_factory, Py_NewRef(Py_None));
-    Py_XSETREF(self->text_factory, Py_NewRef(&PyUnicode_Type));
-
-    set_callback_context(&self->trace_ctx, NULL);
-    set_callback_context(&self->progress_ctx, NULL);
-    set_callback_context(&self->authorizer_ctx, NULL);
+    self->row_factory = Py_NewRef(Py_None);
+    self->text_factory = Py_NewRef(&PyUnicode_Type);
+    self->trace_ctx = NULL;
+    self->progress_ctx = NULL;
+    self->authorizer_ctx = NULL;
 
     self->Warning               = state->Warning;
     self->Error                 = state->Error;

From 93fb30a08e8ab4d7862203421b3d34a321e417d5 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 22:22:15 +0200
Subject: [PATCH 04/18] Make room for and include null terminator

---
 Modules/_sqlite/connection.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 4ced9f5c783196..c6729c3208ac57 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -46,11 +46,11 @@ clinic_fsconverter(PyObject *pathlike, const char **result)
     else if (PyBytes_AsStringAndSize(bytes, &str, &len) < 0) {
         goto error;
     }
-    else if ((*result = PyMem_Malloc(len))) {
+    else if ((*result = (const char *)PyMem_Malloc(len+1)) == NULL) {
         goto error;
     }
 
-    memcpy((void *)(*result), str, len);
+    memcpy((void *)(*result), str, len+1);
     Py_DECREF(bytes);
     return 1;
 

From 0581d1f30efda318406a1744d16a5aa4bf7abe6b Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 22:24:01 +0200
Subject: [PATCH 05/18] Allow threads while closing database

---
 Modules/_sqlite/connection.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index c6729c3208ac57..5b25377e7a2068 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -318,7 +318,12 @@ connection_close(pysqlite_Connection *self)
 {
     if (self->db) {
         clear_sqlite_callbacks(self);
-        int rc = sqlite3_close_v2(self->db);
+
+        int rc;
+        Py_BEGIN_ALLOW_THREADS
+        rc = sqlite3_close_v2(self->db);
+        Py_END_ALLOW_THREADS
+
         assert(rc == SQLITE_OK), (void)rc;
         self->db = NULL;
     }

From ff81aff9a24d27daf92ea2b96d6d21dae778eefe Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 22:33:27 +0200
Subject: [PATCH 06/18] Add borrowed refs comment

---
 Modules/_sqlite/connection.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 5b25377e7a2068..4063a585931440 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -199,6 +199,7 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     self->progress_ctx = NULL;
     self->authorizer_ctx = NULL;
 
+    // Borrowed refs
     self->Warning               = state->Warning;
     self->Error                 = state->Error;
     self->InterfaceError        = state->InterfaceError;

From c30f06b458c8113e1df64b5c9c905c1e9e8615eb Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 22:47:11 +0200
Subject: [PATCH 07/18] Improve naming: cached_statements => cache_size

---
 Modules/_sqlite/clinic/connection.c.h | 12 ++++++------
 Modules/_sqlite/connection.c          |  8 ++++----
 2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/Modules/_sqlite/clinic/connection.c.h b/Modules/_sqlite/clinic/connection.c.h
index bf5a58d7756c9e..a7a65926bfa4fd 100644
--- a/Modules/_sqlite/clinic/connection.c.h
+++ b/Modules/_sqlite/clinic/connection.c.h
@@ -7,7 +7,7 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
                               const char *database, double timeout,
                               int detect_types, PyObject *isolation_level,
                               int check_same_thread, PyObject *factory,
-                              int cached_statements, int uri);
+                              int cache_size, int uri);
 
 static int
 pysqlite_connection_init(PyObject *self, PyObject *args, PyObject *kwargs)
@@ -25,7 +25,7 @@ pysqlite_connection_init(PyObject *self, PyObject *args, PyObject *kwargs)
     PyObject *isolation_level = NULL;
     int check_same_thread = 1;
     PyObject *factory = (PyObject*)clinic_state()->ConnectionType;
-    int cached_statements = 128;
+    int cache_size = 128;
     int uri = 0;
 
     fastargs = _PyArg_UnpackKeywords(_PyTuple_CAST(args)->ob_item, nargs, kwargs, NULL, &_parser, 1, 8, 0, argsbuf);
@@ -84,8 +84,8 @@ pysqlite_connection_init(PyObject *self, PyObject *args, PyObject *kwargs)
         }
     }
     if (fastargs[6]) {
-        cached_statements = _PyLong_AsInt(fastargs[6]);
-        if (cached_statements == -1 && PyErr_Occurred()) {
+        cache_size = _PyLong_AsInt(fastargs[6]);
+        if (cache_size == -1 && PyErr_Occurred()) {
             goto exit;
         }
         if (!--noptargs) {
@@ -97,7 +97,7 @@ pysqlite_connection_init(PyObject *self, PyObject *args, PyObject *kwargs)
         goto exit;
     }
 skip_optional_pos:
-    return_value = pysqlite_connection_init_impl((pysqlite_Connection *)self, database, timeout, detect_types, isolation_level, check_same_thread, factory, cached_statements, uri);
+    return_value = pysqlite_connection_init_impl((pysqlite_Connection *)self, database, timeout, detect_types, isolation_level, check_same_thread, factory, cache_size, uri);
 
 exit:
     /* Cleanup for database */
@@ -819,4 +819,4 @@ pysqlite_connection_exit(pysqlite_Connection *self, PyObject *const *args, Py_ss
 #ifndef PYSQLITE_CONNECTION_LOAD_EXTENSION_METHODDEF
     #define PYSQLITE_CONNECTION_LOAD_EXTENSION_METHODDEF
 #endif /* !defined(PYSQLITE_CONNECTION_LOAD_EXTENSION_METHODDEF) */
-/*[clinic end generated code: output=5b7268875f33c016 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=dd10b1f80c3ba3d3 input=a9049054013a1b77]*/
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 4063a585931440..4ef5b6025be944 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -129,7 +129,7 @@ _sqlite3.Connection.__init__ as pysqlite_connection_init
     isolation_level: object = NULL
     check_same_thread: bool(accept={int}) = True
     factory: object(c_default='(PyObject*)clinic_state()->ConnectionType') = ConnectionType
-    cached_statements: int = 128
+    cached_statements as cache_size: int = 128
     uri: bool = False
 [clinic start generated code]*/
 
@@ -138,8 +138,8 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
                               const char *database, double timeout,
                               int detect_types, PyObject *isolation_level,
                               int check_same_thread, PyObject *factory,
-                              int cached_statements, int uri)
-/*[clinic end generated code: output=bc39e55eb0b68783 input=f8d1f7efc0d84104]*/
+                              int cache_size, int uri)
+/*[clinic end generated code: output=ded53c0781f8fb58 input=3588bcf7e2987e6a]*/
 {
     if (PySys_Audit("sqlite3.connect", "s", database) < 0) {
         return -1;
@@ -176,7 +176,7 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
         return -1;
     }
 
-    PyObject *cache = new_statement_cache(self, state, cached_statements);
+    PyObject *cache = new_statement_cache(self, state, cache_size);
     if (cache == NULL) {
         Py_DECREF(cursors);
         return -1;

From 401a1f0c34f935b13854550b4cea660a2416145c Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 23:12:11 +0200
Subject: [PATCH 08/18] Add tests

---
 Lib/sqlite3/test/dbapi.py | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index 89f773daf24a16..a58d38e37dfa0f 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -331,6 +331,21 @@ def test_drop_unused_refs(self):
             cu = self.cx.execute(f"select {n}")
             self.assertEqual(cu.fetchone()[0], n)
 
+    def test_connection_reinit(self):
+        db = ":memory:"
+        cx = sqlite.connect(db)
+        cx.__init__(db)
+
+    def test_connection_bad_reinit(self):
+        cx = sqlite.connect(":memory:")
+        with temp_dir() as db:
+            try:
+                cx.__init__(db)
+            except sqlite.OperationalError:
+                pass
+            else:
+                self.fail("Unexpected success")
+
 
 class UninitialisedConnectionTests(unittest.TestCase):
     def setUp(self):

From 6d684b4ea477547912781a6c411a0cb39368b99e Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 23:13:13 +0200
Subject: [PATCH 09/18] Adjustments

---
 Modules/_sqlite/connection.c | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 4ef5b6025be944..973a3545959878 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -146,9 +146,9 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     }
 
     if (self->initialized) {
-        connection_close(self);
         PyTypeObject *tp = Py_TYPE(self);
         tp->tp_clear((PyObject *)self);
+        connection_close(self);
         self->initialized = 0;
     }
 
@@ -170,18 +170,6 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
         return -1;
     }
 
-    // Create cursor weak ref list and statement cache
-    PyObject *cursors = PyList_New(0);
-    if (cursors == NULL) {
-        return -1;
-    }
-
-    PyObject *cache = new_statement_cache(self, state, cache_size);
-    if (cache == NULL) {
-        Py_DECREF(cursors);
-        return -1;
-    }
-
     // Init connection state members
     self->db = db;
     self->state = state;
@@ -190,8 +178,8 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     self->begin_statement = NULL;
     self->check_same_thread = check_same_thread;
     self->thread_ident = PyThread_get_thread_ident();
-    self->statement_cache = cache;
-    self->cursors = cursors;
+    self->statement_cache = new_statement_cache(self, state, cache_size);;
+    self->cursors = PyList_New(0);
     self->created_cursors = 0;
     self->row_factory = Py_NewRef(Py_None);
     self->text_factory = Py_NewRef(&PyUnicode_Type);
@@ -211,6 +199,10 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     self->ProgrammingError      = state->ProgrammingError;
     self->NotSupportedError     = state->NotSupportedError;
 
+    if (self->cursors == NULL || self->statement_cache == NULL) {
+        return -1;
+    }
+
     // Set isolation level at last, since it may trigger a COMMIT
     if (isolation_level == NULL) {
         isolation_level = PyUnicode_FromString("");
@@ -318,10 +310,9 @@ static void
 connection_close(pysqlite_Connection *self)
 {
     if (self->db) {
-        clear_sqlite_callbacks(self);
-
         int rc;
         Py_BEGIN_ALLOW_THREADS
+        clear_sqlite_callbacks(self);
         rc = sqlite3_close_v2(self->db);
         Py_END_ALLOW_THREADS
 

From 4f55bb85d7a5f0d620c459d3a769cc16582f3309 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 23:31:33 +0200
Subject: [PATCH 10/18] Upgrade "bad reinit" test to include Petr's reproducer

---
 Lib/sqlite3/test/dbapi.py | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index a58d38e37dfa0f..eac3b2b36751ea 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -338,13 +338,16 @@ def test_connection_reinit(self):
 
     def test_connection_bad_reinit(self):
         cx = sqlite.connect(":memory:")
+        with cx:
+            cx.execute("create table t(t)")
         with temp_dir() as db:
-            try:
-                cx.__init__(db)
-            except sqlite.OperationalError:
-                pass
-            else:
-                self.fail("Unexpected success")
+            self.assertRaisesRegex(sqlite.OperationalError,
+                                   "unable to open database file",
+                                   cx.__init__, db)
+            self.assertRaisesRegex(sqlite.ProgrammingError,
+                                   "Base Connection.__init__ not called",
+                                   cx.executemany, "insert into t values(?)",
+                                   ((v,) for v in range(3)))
 
 
 class UninitialisedConnectionTests(unittest.TestCase):

From 87903ff64db99ef7203bb40a02012057d4eeb702 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Tue, 7 Sep 2021 23:39:17 +0200
Subject: [PATCH 11/18] Always free callback contexts after closing database

---
 Modules/_sqlite/connection.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 973a3545959878..f38a3bb1fbbf9f 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -306,6 +306,14 @@ clear_sqlite_callbacks(pysqlite_Connection *self)
 #endif
 }
 
+static void
+free_callback_contexts(pysqlite_Connection *self)
+{
+    set_callback_context(&self->trace_ctx, NULL);
+    set_callback_context(&self->progress_ctx, NULL);
+    set_callback_context(&self->authorizer_ctx, NULL);
+}
+
 static void
 connection_close(pysqlite_Connection *self)
 {
@@ -315,20 +323,13 @@ connection_close(pysqlite_Connection *self)
         clear_sqlite_callbacks(self);
         rc = sqlite3_close_v2(self->db);
         Py_END_ALLOW_THREADS
+        free_callback_contexts(self);
 
         assert(rc == SQLITE_OK), (void)rc;
         self->db = NULL;
     }
 }
 
-static void
-free_callback_contexts(pysqlite_Connection *self)
-{
-    set_callback_context(&self->trace_ctx, NULL);
-    set_callback_context(&self->progress_ctx, NULL);
-    set_callback_context(&self->authorizer_ctx, NULL);
-}
-
 static void
 connection_dealloc(pysqlite_Connection *self)
 {
@@ -338,7 +339,6 @@ connection_dealloc(pysqlite_Connection *self)
 
     /* Clean up if user has not called .close() explicitly. */
     connection_close(self);
-    free_callback_contexts(self);
 
     tp->tp_free(self);
     Py_DECREF(tp);

From 73c200604fabea9dbb76ce2fb0e479c7f040497a Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Wed, 8 Sep 2021 10:48:01 +0200
Subject: [PATCH 12/18] Improve "good" reinit test

---
 Lib/sqlite3/test/dbapi.py | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index eac3b2b36751ea..be9deec59376e3 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -334,7 +334,27 @@ def test_drop_unused_refs(self):
     def test_connection_reinit(self):
         db = ":memory:"
         cx = sqlite.connect(db)
+        cx.text_factory = bytes
+        cx.row_factory = sqlite.Row
+        cu = cx.cursor()
+        cu.execute("create table foo (bar)")
+        cu.executemany("insert into foo (bar) values (?)",
+                       ((str(v),) for v in range(4)))
+        cu.execute("select bar from foo")
+
+        rows = [r for r in cu.fetchmany(2)]
+        self.assertTrue(all(isinstance(r, sqlite.Row) for r in rows))
+        self.assertEqual([r[0] for r in rows], [b"0", b"1"])
+
         cx.__init__(db)
+        cx.execute("create table foo (bar)")
+        cx.executemany("insert into foo (bar) values (?)",
+                       ((v,) for v in ("a", "b", "c", "d")))
+
+        # This uses the old database, old row factory, but new text factory
+        rows = [r for r in cu.fetchall()]
+        self.assertTrue(all(isinstance(r, sqlite.Row) for r in rows))
+        self.assertEqual([r[0] for r in rows], ["2", "3"])
 
     def test_connection_bad_reinit(self):
         cx = sqlite.connect(":memory:")

From 4b064437b899921ce302ea46e23418b6cdb72b29 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Wed, 8 Sep 2021 11:00:26 +0200
Subject: [PATCH 13/18] Deprecate reinitialisation

---
 Lib/sqlite3/test/dbapi.py    | 13 +++++++++----
 Modules/_sqlite/connection.c |  7 +++++++
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index be9deec59376e3..7fddebfa7da62b 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -346,7 +346,10 @@ def test_connection_reinit(self):
         self.assertTrue(all(isinstance(r, sqlite.Row) for r in rows))
         self.assertEqual([r[0] for r in rows], [b"0", b"1"])
 
-        cx.__init__(db)
+        with self.assertWarns(DeprecationWarning) as cm:
+            cx.__init__(db)
+        self.assertIn("dbapi.py", cm.filename)
+
         cx.execute("create table foo (bar)")
         cx.executemany("insert into foo (bar) values (?)",
                        ((v,) for v in ("a", "b", "c", "d")))
@@ -361,9 +364,11 @@ def test_connection_bad_reinit(self):
         with cx:
             cx.execute("create table t(t)")
         with temp_dir() as db:
-            self.assertRaisesRegex(sqlite.OperationalError,
-                                   "unable to open database file",
-                                   cx.__init__, db)
+            with self.assertWarns(DeprecationWarning) as cm:
+                msg = "unable to open database file"
+                with self.assertRaisesRegex(sqlite.OperationalError, msg):
+                    cx.__init__(db)
+            self.assertIn("dbapi.py", cm.filename)
             self.assertRaisesRegex(sqlite.ProgrammingError,
                                    "Base Connection.__init__ not called",
                                    cx.executemany, "insert into t values(?)",
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index f38a3bb1fbbf9f..2301ed600a91fd 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -146,6 +146,13 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     }
 
     if (self->initialized) {
+        int rc = PyErr_WarnEx(PyExc_DeprecationWarning,
+                              "Connection reinitialization is deprecated and "
+                              "will be removed in Python 3.13",
+                              1);
+        if (rc < 0) {
+            return -1;
+        }
         PyTypeObject *tp = Py_TYPE(self);
         tp->tp_clear((PyObject *)self);
         connection_close(self);

From cec8f717f7d62e0026e36f0adcd676883dd1ac32 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Wed, 8 Sep 2021 11:24:46 +0200
Subject: [PATCH 14/18] SQLite will clear callbacks when closing; remove
 explicit close

---
 Modules/_sqlite/connection.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 2301ed600a91fd..3bc7c1d5e73e26 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -301,18 +301,6 @@ connection_clear(pysqlite_Connection *self)
     return 0;
 }
 
-static void
-clear_sqlite_callbacks(pysqlite_Connection *self)
-{
-    (void)sqlite3_set_authorizer(self->db, NULL, NULL);
-    sqlite3_progress_handler(self->db, 0, NULL, NULL);
-#ifdef HAVE_TRACE_V2
-    sqlite3_trace_v2(self->db, SQLITE_TRACE_STMT, NULL, NULL);
-#else
-    sqlite3_trace(self->db, NULL, NULL);
-#endif
-}
-
 static void
 free_callback_contexts(pysqlite_Connection *self)
 {
@@ -327,7 +315,6 @@ connection_close(pysqlite_Connection *self)
     if (self->db) {
         int rc;
         Py_BEGIN_ALLOW_THREADS
-        clear_sqlite_callbacks(self);
         rc = sqlite3_close_v2(self->db);
         Py_END_ALLOW_THREADS
         free_callback_contexts(self);

From cb96a4064f6de518b46716b48047fee9dafeebe1 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Fri, 10 Sep 2021 06:29:42 +0200
Subject: [PATCH 15/18] Revert "Deprecate reinitialisation"

This reverts commit 4b064437b899921ce302ea46e23418b6cdb72b29.
---
 Lib/sqlite3/test/dbapi.py    | 13 ++++---------
 Modules/_sqlite/connection.c |  7 -------
 2 files changed, 4 insertions(+), 16 deletions(-)

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index 7fddebfa7da62b..be9deec59376e3 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -346,10 +346,7 @@ def test_connection_reinit(self):
         self.assertTrue(all(isinstance(r, sqlite.Row) for r in rows))
         self.assertEqual([r[0] for r in rows], [b"0", b"1"])
 
-        with self.assertWarns(DeprecationWarning) as cm:
-            cx.__init__(db)
-        self.assertIn("dbapi.py", cm.filename)
-
+        cx.__init__(db)
         cx.execute("create table foo (bar)")
         cx.executemany("insert into foo (bar) values (?)",
                        ((v,) for v in ("a", "b", "c", "d")))
@@ -364,11 +361,9 @@ def test_connection_bad_reinit(self):
         with cx:
             cx.execute("create table t(t)")
         with temp_dir() as db:
-            with self.assertWarns(DeprecationWarning) as cm:
-                msg = "unable to open database file"
-                with self.assertRaisesRegex(sqlite.OperationalError, msg):
-                    cx.__init__(db)
-            self.assertIn("dbapi.py", cm.filename)
+            self.assertRaisesRegex(sqlite.OperationalError,
+                                   "unable to open database file",
+                                   cx.__init__, db)
             self.assertRaisesRegex(sqlite.ProgrammingError,
                                    "Base Connection.__init__ not called",
                                    cx.executemany, "insert into t values(?)",
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 3bc7c1d5e73e26..59091f25c4776d 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -146,13 +146,6 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     }
 
     if (self->initialized) {
-        int rc = PyErr_WarnEx(PyExc_DeprecationWarning,
-                              "Connection reinitialization is deprecated and "
-                              "will be removed in Python 3.13",
-                              1);
-        if (rc < 0) {
-            return -1;
-        }
         PyTypeObject *tp = Py_TYPE(self);
         tp->tp_clear((PyObject *)self);
         connection_close(self);

From f3a1f39c5e993bc79437b56628640ae4128b3718 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Mon, 18 Oct 2021 14:02:28 +0200
Subject: [PATCH 16/18] Clear database pointer before calling
 sqlite3_close_v2()

---
 Modules/_sqlite/connection.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index e10c8c9849a7d0..8d80bcaeb5460f 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -306,14 +306,15 @@ static void
 connection_close(pysqlite_Connection *self)
 {
     if (self->db) {
-        int rc;
-        Py_BEGIN_ALLOW_THREADS
-        rc = sqlite3_close_v2(self->db);
-        Py_END_ALLOW_THREADS
         free_callback_contexts(self);
 
-        assert(rc == SQLITE_OK), (void)rc;
+        sqlite3 *db = self->db;
         self->db = NULL;
+
+        Py_BEGIN_ALLOW_THREADS
+        int rc = sqlite3_close_v2(db);
+        assert(rc == SQLITE_OK), (void)rc;
+        Py_END_ALLOW_THREADS
     }
 }
 

From 82e1f5ebbfa1abe139d1296bff5f166cf9e48325 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Mon, 15 Nov 2021 10:36:05 +0100
Subject: [PATCH 17/18] Fix merge

---
 Modules/_sqlite/connection.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 71af9b82430ca6..a5d76e394e717e 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -208,7 +208,7 @@ pysqlite_connection_init_impl(pysqlite_Connection *self,
     }
 
     // Create LRU statement cache; returns a new reference.
-    PyObject *statement_cache = new_statement_cache(self, cached_statements);
+    PyObject *statement_cache = new_statement_cache(self, state, cache_size);
     if (statement_cache == NULL) {
         return -1;
     }

From 83f67368a69fe069f94735e27c14c38004ddd8c5 Mon Sep 17 00:00:00 2001
From: "Erlend E. Aasland" <erlend.aasland@innova.no>
Date: Mon, 15 Nov 2021 10:50:13 +0100
Subject: [PATCH 18/18] bpo-45512: Raise sqlite3.Connection.__init__ is called
 with bad isolation level

---
 Lib/test/test_sqlite3/test_dbapi.py | 12 ++++++++++--
 Modules/_sqlite/connection.c        |  6 +++---
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/Lib/test/test_sqlite3/test_dbapi.py b/Lib/test/test_sqlite3/test_dbapi.py
index 3055b6d295cf87..4b387cb952455a 100644
--- a/Lib/test/test_sqlite3/test_dbapi.py
+++ b/Lib/test/test_sqlite3/test_dbapi.py
@@ -48,8 +48,8 @@ def managed_connect(*args, in_mem=False, **kwargs):
 
 
 # Helper for temporary memory databases
-def memory_database():
-    cx = sqlite.connect(":memory:")
+def memory_database(*args, **kwargs):
+    cx = sqlite.connect(":memory:", *args, **kwargs)
     return contextlib.closing(cx)
 
 
@@ -547,6 +547,14 @@ def test_connection_bad_reinit(self):
                                    cx.executemany, "insert into t values(?)",
                                    ((v,) for v in range(3)))
 
+    def test_connection_init_bad_isolation_level(self):
+        msg = (
+            "isolation_level string must be '', 'DEFERRED', 'IMMEDIATE', or "
+            "'EXCLUSIVE'"
+        )
+        with self.assertRaisesRegex(ValueError, msg):
+            memory_database(isolation_level="BOGUS")
+
 
 class UninitialisedConnectionTests(unittest.TestCase):
     def setUp(self):
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index a5d76e394e717e..e7947671db3544 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -129,6 +129,9 @@ get_begin_statement(const char *level)
             return begin_statements[i];
         }
     }
+    PyErr_SetString(PyExc_ValueError,
+                    "isolation_level string must be '', 'DEFERRED', "
+                    "'IMMEDIATE', or 'EXCLUSIVE'");
     return NULL;
 }
 
@@ -1399,9 +1402,6 @@ pysqlite_connection_set_isolation_level(pysqlite_Connection* self, PyObject* iso
         }
         const char *stmt = get_begin_statement(cstr_level);
         if (stmt == NULL) {
-            PyErr_SetString(PyExc_ValueError,
-                            "isolation_level string must be '', 'DEFERRED', "
-                            "'IMMEDIATE', or 'EXCLUSIVE'");
             return -1;
         }
         self->begin_statement = stmt;