Fixed bug when binding a temporary LOB IN/OUT to a PL/SQL procedure

(#468).

Author: anthony-tuininga

doc/src/release_notes.rst

@@ -27,6 +27,8 @@ Thin Mode Changes
     (`issue 456 <https://github.com/oracle/python-oracledb/issues/456>`__).
 #)  Fixed wildcard matching of domains in Subject Alternative Names
     (`issue 462 <https://github.com/oracle/python-oracledb/issues/462>`__).
+#)  Fixed bug when binding a temporary LOB IN/OUT to a PL/SQL procedure
+    (`issue 468 <https://github.com/oracle/python-oracledb/issues/468>`__).
 
 Thick Mode Changes
 ++++++++++++++++++

src/oracledb/impl/thin/messages/base.pyx

@@ -893,8 +893,11 @@ cdef class MessageWithData(Message):
         elif ora_type_num in (ORA_TYPE_NUM_CLOB,
                               ORA_TYPE_NUM_BLOB,
                               ORA_TYPE_NUM_BFILE):
+            if not self.in_fetch:
+                column_value = var_impl._values[pos]
             column_value = buf.read_lob_with_length(self.conn_impl,
-                                                    metadata.dbtype)
+                                                    metadata.dbtype,
+                                                    column_value)
         elif ora_type_num == ORA_TYPE_NUM_JSON:
             column_value = buf.read_oson()
         elif ora_type_num == ORA_TYPE_NUM_VECTOR:

src/oracledb/impl/thin/packet.pyx

@@ -475,7 +475,7 @@ cdef class ReadBuffer(Buffer):
             return decoder.decode(data)
 
     cdef object read_lob_with_length(self, BaseThinConnImpl conn_impl,
-                                     DbType dbtype):
+                                     DbType dbtype, object lob):
         """
         Read a LOB locator from the buffer and return a LOB object containing
         it.
@@ -484,6 +484,7 @@ cdef class ReadBuffer(Buffer):
             uint32_t chunk_size, num_bytes
             BaseThinLobImpl lob_impl
             uint64_t size
+            bytes locator
             type cls
         self.read_ub4(&num_bytes)
         if num_bytes > 0:
@@ -492,15 +493,21 @@ cdef class ReadBuffer(Buffer):
             else:
                 self.read_ub8(&size)
                 self.read_ub4(&chunk_size)
-            lob_impl = conn_impl._create_lob_impl(dbtype, self.read_bytes())
+            locator = self.read_bytes()
+            if lob is None:
+                lob_impl = conn_impl._create_lob_impl(dbtype, locator)
+                cls = PY_TYPE_ASYNC_LOB \
+                        if conn_impl._protocol._transport._is_async \
+                        else PY_TYPE_LOB
+                lob = cls._from_impl(lob_impl)
+            else:
+                lob_impl = lob._impl
+                lob_impl._locator = locator
             lob_impl._size = size
             lob_impl._chunk_size = chunk_size
             lob_impl._has_metadata = \
                     dbtype._ora_type_num != ORA_TYPE_NUM_BFILE
-            cls = PY_TYPE_ASYNC_LOB \
-                    if conn_impl._protocol._transport._is_async \
-                    else PY_TYPE_LOB
-            return cls._from_impl(lob_impl)
+            return lob
 
     cdef const char_type* read_raw_bytes(self, ssize_t num_bytes) except NULL:
         """

tests/sql/create_schema.sql

@@ -1479,6 +1479,12 @@ create or replace package &main_user..pkg_TestLOBs as
         a_Size                          out number
     );
 
+    procedure TestInOut (
+        a_CLOB                          in out clob,
+        a_SearchValue                   varchar2,
+        a_ReplaceValue                  varchar2
+    );
+
 end;
 /
 
@@ -1500,5 +1506,16 @@ create or replace package body &main_user..pkg_TestLOBs as
         a_Size := dbms_lob.getlength(a_CLOB);
     end;
 
+    procedure TestInOut (
+        a_CLOB                          in out clob,
+        a_SearchValue                   varchar2,
+        a_ReplaceValue                  varchar2
+    ) is
+    begin
+        if a_SearchValue is not null then
+            a_CLOB := replace(a_CLOB, a_SearchValue, a_ReplaceValue);
+        end if;
+    end;
+
 end;
 /

tests/test_1900_lob_var.py

@@ -1,5 +1,5 @@
 # -----------------------------------------------------------------------------
-# Copyright (c) 2020, 2024, Oracle and/or its affiliates.
+# Copyright (c) 2020, 2025, Oracle and/or its affiliates.
 #
 # This software is dual-licensed to you under the Universal Permissive License
 # (UPL) 1.0 as shown at https://oss.oracle.com/licenses/upl and Apache License
@@ -614,6 +614,29 @@ def test_1938(self):
             var.setvalue(0, lob)
             self.assertIs(var.getvalue(), lob)
 
+    def test_1939(self):
+        "1939 - temporary LOB in/out without modification"
+        value = "test - 1939"
+        var = self.cursor.var(oracledb.DB_TYPE_CLOB)
+        var.setvalue(0, value)
+        self.assertEqual(var.getvalue().read(), value)
+        self.cursor.callproc("pkg_TestLOBs.TestInOut", [var, None, None])
+        self.assertEqual(var.getvalue().read(), value)
+
+    def test_1940(self):
+        "1940 - temporary LOB in/out with modification"
+        search_value = "test"
+        replace_value = "replaced"
+        initial_value = f"{search_value} - 1939"
+        final_value = f"{replace_value} - 1939"
+        var = self.cursor.var(oracledb.DB_TYPE_CLOB)
+        var.setvalue(0, initial_value)
+        self.assertEqual(var.getvalue().read(), initial_value)
+        self.cursor.callproc(
+            "pkg_TestLOBs.TestInOut", [var, search_value, replace_value]
+        )
+        self.assertEqual(var.getvalue().read(), final_value)
+
 
 if __name__ == "__main__":
     test_env.run_test_cases()