postgres.git / summary / log / commit / refs

commit    d4545dc19b8ea670bf62e06d22b0e4e6fcb45153
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Mon Mar 08 23:54:55 2021 +0000
First released in: 14.0

    Complain if a function-in-FROM returns a set when it shouldn't.
    
    Throw a "function protocol violation" error if a function in FROM
    tries to return a set though it wasn't marked proretset.  Although
    such cases work at the moment, it doesn't seem like something we
    want to guarantee will keep working.  Besides, there are other
    negative consequences of not setting the proretset flag, such as
    potentially bad plans.
    
    No back-patch, since if there is any third-party code violating
    this expectation, people wouldn't appreciate us breaking it in
    a minor release.
    
    Discussion: https://postgr.es/m/1636062.1615141782@sss.pgh.pa.us


 src/backend/executor/execSRF.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/backend/executor/execSRF.c b/src/backend/executor/execSRF.c
index 8aec3b549bd..545b6c19dac 100644
--- a/src/backend/executor/execSRF.c
+++ b/src/backend/executor/execSRF.c
@@ -353,11 +353,21 @@ ExecMakeTableFunctionResult(SetExprState *setexpr,
 			 */
 			if (rsinfo.isDone != ExprMultipleResult)
 				break;
+
+			/*
+			 * Check that set-returning functions were properly declared.
+			 * (Note: for historical reasons, we don't complain if a non-SRF
+			 * returns ExprEndResult; that's treated as returning NULL.)
+			 */
+			if (!returnsSet)
+				ereport(ERROR,
+						(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
+						 errmsg("table-function protocol for value-per-call mode was not followed")));
 		}
 		else if (rsinfo.returnMode == SFRM_Materialize)
 		{
 			/* check we're on the same page as the function author */
-			if (!first_time || rsinfo.isDone != ExprSingleResult)
+			if (!first_time || rsinfo.isDone != ExprSingleResult || !returnsSet)
 				ereport(ERROR,
 						(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
 						 errmsg("table-function protocol for materialize mode was not followed")));


[parent: fed10d4eec79]