Don't crash on empty statements in SQL-standard function bodies.

tglsfdc · tglsfdc · commit bfeede9fa464 · 2021-06-08T11:59:34.000-04:00
gram.y should discard NULL pointers (empty statements) when assembling a routine_body_stmt_list, as it does for other sorts of statement lists. Julien Rouhaud and Tom Lane, per report from Noah Misch. Discussion: https://postgr.es/m/20210606044418.GA297923@rfd.leadboat.com
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
@@ -7990,7 +7990,11 @@ opt_routine_body:
 routine_body_stmt_list:
 			routine_body_stmt_list routine_body_stmt ';'
 				{
-					$$ = lappend($1, $2);
+					/* As in stmtmulti, discard empty statements */
+					if ($2 != NULL)
+						$$ = lappend($1, $2);
+					else
+						$$ = $1;
 				}
 			| /*EMPTY*/
 				{
diff --git a/src/test/regress/expected/create_function_3.out b/src/test/regress/expected/create_function_3.out
@@ -267,7 +267,7 @@ CREATE FUNCTION functest_S_3() RETURNS boolean
     RETURN false;
 CREATE FUNCTION functest_S_3a() RETURNS boolean
     BEGIN ATOMIC
-        RETURN false;
+        ;;RETURN false;;
     END;
 CREATE FUNCTION functest_S_10(a text, b date) RETURNS boolean
     LANGUAGE SQL
diff --git a/src/test/regress/sql/create_function_3.sql b/src/test/regress/sql/create_function_3.sql
@@ -165,7 +165,7 @@ CREATE FUNCTION functest_S_3() RETURNS boolean
     RETURN false;
 CREATE FUNCTION functest_S_3a() RETURNS boolean
     BEGIN ATOMIC
-        RETURN false;
+        ;;RETURN false;;
     END;
 
 CREATE FUNCTION functest_S_10(a text, b date) RETURNS boolean

Original file line number	Diff line number	Diff line change
`@@ -7990,7 +7990,11 @@ opt_routine_body:`
`7990`	`7990`	`routine_body_stmt_list:`
`7991`	`7991`	`routine_body_stmt_list routine_body_stmt ';'`
`7992`	`7992`	`{`
`7993`		`- $$ = lappend($1, $2);`
	`7993`	`+ /* As in stmtmulti, discard empty statements */`
	`7994`	`+ if ($2 != NULL)`
	`7995`	`+ $$ = lappend($1, $2);`
	`7996`	`+ else`
	`7997`	`+ $$ = $1;`
`7994`	`7998`	`}`
`7995`	`7999`	`\| /EMPTY/`
`7996`	`8000`	`{`