Revert "bpo-44041: Only call sqlite3_column_count() if needed"

This reverts commit f961c3f.

Author: Erlend E. Aasland

Modules/_sqlite/cursor.c

@@ -167,8 +167,7 @@ pysqlite_build_row_cast_map(pysqlite_Cursor* self)
         return -1;
     }
 
-    int column_count = self->statement->column_count;
-    for (i = 0; i < column_count; i++) {
+    for (i = 0; i < sqlite3_column_count(self->statement->st); i++) {
         converter = NULL;
 
         if (self->connection->detect_types & PARSE_COLNAMES) {
@@ -560,7 +559,9 @@ _pysqlite_query_execute(pysqlite_Cursor* self, int multiple, PyObject* operation
         }
 
         assert(rc == SQLITE_ROW || rc == SQLITE_DONE);
-        numcols = self->statement->column_count;
+        Py_BEGIN_ALLOW_THREADS
+        numcols = sqlite3_column_count(self->statement->st);
+        Py_END_ALLOW_THREADS
         if (self->description == Py_None && numcols > 0) {
             Py_SETREF(self->description, PyTuple_New(numcols));
             if (!self->description) {

Modules/_sqlite/statement.c

@@ -89,7 +89,6 @@ pysqlite_statement_create(pysqlite_Connection *connection, PyObject *sql)
     self->sql = Py_NewRef(sql);
     self->in_use = 0;
     self->is_dml = 0;
-    self->column_count = 0;
     self->in_weakreflist = NULL;
 
     /* Determine if the statement is a DML statement.
@@ -133,13 +132,6 @@ pysqlite_statement_create(pysqlite_Connection *connection, PyObject *sql)
         goto error;
     }
 
-    /* Set column count just before returning, to minimise SQLite API calls */
-    if (!self->is_dml) {
-        Py_BEGIN_ALLOW_THREADS
-        self->column_count = sqlite3_column_count(self->st);
-        Py_END_ALLOW_THREADS
-    }
-
     return self;
 
 error:

Modules/_sqlite/statement.h

@@ -37,7 +37,6 @@ typedef struct
     PyObject* sql;
     int in_use;
     int is_dml;
-    int column_count;
     PyObject* in_weakreflist; /* List of weak references */
 } pysqlite_Statement;