From 54d67febd7d26b5e17c365e3b91d96698d79ef11 Mon Sep 17 00:00:00 2001
From: Xing Guo <higuoxing@gmail.com>
Date: Tue, 14 Jul 2026 16:12:00 +0800
Subject: [PATCH v1] plpython: pair SPI_connect and SPI_finish in the same
 function

PL/Python's call_handler, inline_handler call SPI_connect_ext() at its
top, but SPI_finish() is called inside execution functions
PLy_exec_function, PLy_exec_trigger, PLy_exec_event_trigger in
plpy_exec.c.  It's easy to miss SPI_finish when adding a new execution
path for PL/Python.

SPI_finish() are moved into the two handlers and paired with
SPI_connect() in the same function.  This matches code patterns in
plpgsql and plperl.
---
 src/pl/plpython/plpy_exec.c | 19 ++++++++-----------
 src/pl/plpython/plpy_main.c | 24 +++++++++---------------
 2 files changed, 17 insertions(+), 26 deletions(-)

diff --git a/src/pl/plpython/plpy_exec.c b/src/pl/plpython/plpy_exec.c
index de7f64113d6..d3b470c48e0 100644
--- a/src/pl/plpython/plpy_exec.c
+++ b/src/pl/plpython/plpy_exec.c
@@ -172,13 +172,13 @@ PLy_exec_function(FunctionCallInfo fcinfo, PLyProcedureCache *pcache)
 		}
 
 		/*
-		 * Disconnect from SPI manager and then create the return values datum
+		 * Switch out of SPI's memory context and then create the return values
+		 * datum
 		 * (if the input function does a palloc for it this must not be
-		 * allocated in the SPI memory context because SPI_finish would free
-		 * it).
+		 * allocated in the SPI memory context because the upper caller would
+		 * call SPI_finish to free it).
 		 */
-		if (SPI_finish() != SPI_OK_FINISH)
-			elog(ERROR, "SPI_finish failed");
+		MemoryContextSwitchTo(fcinfo->flinfo->fn_mcxt);
 
 		plerrcontext.callback = plpython_return_error_callback;
 		plerrcontext.previous = error_context_stack;
@@ -439,10 +439,10 @@ PLy_exec_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc)
 		Assert(plrv != NULL);
 
 		/*
-		 * Disconnect from SPI manager
+		 * Switch out of SPI's memory context so that trigger result
+		 * processing doesn't allocate inside SPI's procedure context.
 		 */
-		if (SPI_finish() != SPI_OK_FINISH)
-			elog(ERROR, "SPI_finish failed");
+		MemoryContextSwitchTo(fcinfo->flinfo->fn_mcxt);
 
 		/*
 		 * return of None means we're happy with the tuple
@@ -527,9 +527,6 @@ PLy_exec_event_trigger(FunctionCallInfo fcinfo, PLyProcedure *proc)
 		Py_DECREF(plttag);
 
 		PLy_procedure_call(proc, "TD", pltdata);
-
-		if (SPI_finish() != SPI_OK_FINISH)
-			elog(ERROR, "SPI_finish() failed");
 	}
 	PG_FINALLY();
 	{
diff --git a/src/pl/plpython/plpy_main.c b/src/pl/plpython/plpy_main.c
index df08d3fbd1b..509e0f4a24b 100644
--- a/src/pl/plpython/plpy_main.c
+++ b/src/pl/plpython/plpy_main.c
@@ -188,7 +188,6 @@ plpython3_call_handler(PG_FUNCTION_ARGS)
 		IsA(fcinfo->context, CallContext) &&
 		!castNode(CallContext, fcinfo->context)->atomic;
 
-	/* Note: SPI_finish() happens in plpy_exec.c, which is dubious design */
 	SPI_connect_ext(nonatomic ? SPI_OPT_NONATOMIC : 0);
 
 	/*
@@ -236,18 +235,16 @@ plpython3_call_handler(PG_FUNCTION_ARGS)
 		else
 			retval = PLy_exec_function(fcinfo, pcache);
 	}
-	PG_CATCH();
+	PG_FINALLY();
 	{
-		/* Destroy the execution context */
+		/* Destroy the execution context on both success and error paths */
 		PLy_pop_execution_context();
 		PyErr_Clear();
-
-		PG_RE_THROW();
 	}
 	PG_END_TRY();
 
-	/* Destroy the execution context */
-	PLy_pop_execution_context();
+	if (SPI_finish() != SPI_OK_FINISH)
+		elog(ERROR, "SPI_finish failed");
 
 	return retval;
 }
@@ -313,20 +310,17 @@ plpython3_inline_handler(PG_FUNCTION_ARGS)
 		exec_ctx->curr_proc = &proc;
 		PLy_exec_function(fake_fcinfo, &pcache);
 	}
-	PG_CATCH();
+	PG_FINALLY();
 	{
+		/* Destroy the execution context on both success and error paths */
 		PLy_pop_execution_context();
-		PLy_procedure_delete(&proc);
 		PyErr_Clear();
-		PG_RE_THROW();
+		PLy_procedure_delete(&proc);
 	}
 	PG_END_TRY();
 
-	/* Destroy the execution context */
-	PLy_pop_execution_context();
-
-	/* Now clean up the transient procedure we made */
-	PLy_procedure_delete(&proc);
+	if (SPI_finish() != SPI_OK_FINISH)
+		elog(ERROR, "SPI_finish failed");
 
 	PG_RETURN_VOID();
 }
-- 
2.50.1 (Apple Git-155)

