Added the const qualifier to char* variables that refer to readonly internal

UTF-8 represenatation of Unicode objects.

Modules/_sqlite/connection.c

@@ -1489,7 +1489,7 @@ pysqlite_connection_create_collation(pysqlite_Connection* self, PyObject* args)
     PyObject* retval;
     Py_ssize_t i, len;
     _Py_IDENTIFIER(upper);
-    char *uppercase_name_str;
+    const char *uppercase_name_str;
     int rc;
     unsigned int kind;
     void *data;

Modules/_sqlite/row.c

@@ -79,12 +79,12 @@ PyObject* pysqlite_row_item(pysqlite_Row* self, Py_ssize_t idx)
 PyObject* pysqlite_row_subscript(pysqlite_Row* self, PyObject* idx)
 {
     Py_ssize_t _idx;
-    char* key;
+    const char *key;
     Py_ssize_t nitems, i;
-    char* compare_key;
+    const char *compare_key;
 
-    char* p1;
-    char* p2;
+    const char *p1;
+    const char *p2;
 
     PyObject* item;
 

Modules/_sqlite/statement.c

@@ -112,7 +112,7 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con
 int pysqlite_statement_bind_parameter(pysqlite_Statement* self, int pos, PyObject* parameter)
 {
     int rc = SQLITE_OK;
-    char* string;
+    const char *string;
     Py_ssize_t buflen;
     parameter_type paramtype;