From b2754115b76231183ded49f608a9db1f806c10e4 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Date: Tue, 28 Apr 2026 12:43:40 +0530
Subject: [PATCH v20260703 04/14] Dropping a property not associated with the
 given label

When dropping a property by name from a label, the code checked only
whether the property existed in the graph's property catalog. It did not
verify that the property was actually associated with the given label,
resulting in passing InvalidOid to performDeletion(). Fix it by
explicilty checking the label property association.

While at it also rearrange the code so as to avoid multiple ereport
calls for the same error in the same block.

Reported by: Chao Li <lic@highgo.com>
Author: Chao Li <lic@highgo.com>
Reviewed by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://postgr.es/m/1DA5D52A-4AFA-426E-83F7-42ED974D682B@gmail.com
---
 src/backend/commands/propgraphcmds.c          | 47 ++++++++-----------
 .../expected/create_property_graph.out        |  2 +
 .../regress/sql/create_property_graph.sql     |  1 +
 3 files changed, 22 insertions(+), 28 deletions(-)

diff --git a/src/backend/commands/propgraphcmds.c b/src/backend/commands/propgraphcmds.c
index 4c0fe763b5c..510cc1ccc03 100644
--- a/src/backend/commands/propgraphcmds.c
+++ b/src/backend/commands/propgraphcmds.c
@@ -1611,7 +1611,7 @@ AlterPropGraph(ParseState *pstate, const AlterPropGraphStmt *stmt)
 		Oid			peoid;
 		Oid			pgerelid;
 		Oid			labeloid;
-		Oid			ellabeloid;
+		Oid			ellabeloid = InvalidOid;
 
 		if (stmt->element_kind == PROPGRAPH_ELEMENT_KIND_VERTEX)
 			peoid = get_vertex_oid(pstate, pgrelid, stmt->element_alias, -1);
@@ -1622,17 +1622,11 @@ AlterPropGraph(ParseState *pstate, const AlterPropGraphStmt *stmt)
 								   Anum_pg_propgraph_label_oid,
 								   ObjectIdGetDatum(pgrelid),
 								   CStringGetDatum(stmt->alter_label));
-		if (!labeloid)
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("property graph \"%s\" element \"%s\" has no label \"%s\"",
-						   get_rel_name(pgrelid), stmt->element_alias, stmt->alter_label),
-					parser_errposition(pstate, -1));
-
-		ellabeloid = GetSysCacheOid2(PROPGRAPHELEMENTLABELELEMENTLABEL,
-									 Anum_pg_propgraph_element_label_oid,
-									 ObjectIdGetDatum(peoid),
-									 ObjectIdGetDatum(labeloid));
+		if (labeloid)
+			ellabeloid = GetSysCacheOid2(PROPGRAPHELEMENTLABELELEMENTLABEL,
+										 Anum_pg_propgraph_element_label_oid,
+										 ObjectIdGetDatum(peoid),
+										 ObjectIdGetDatum(labeloid));
 		if (!ellabeloid)
 			ereport(ERROR,
 					errcode(ERRCODE_UNDEFINED_OBJECT),
@@ -1653,7 +1647,7 @@ AlterPropGraph(ParseState *pstate, const AlterPropGraphStmt *stmt)
 	{
 		Oid			peoid;
 		Oid			labeloid;
-		Oid			ellabeloid;
+		Oid			ellabeloid = InvalidOid;
 		ObjectAddress obj;
 
 		if (stmt->element_kind == PROPGRAPH_ELEMENT_KIND_VERTEX)
@@ -1665,17 +1659,11 @@ AlterPropGraph(ParseState *pstate, const AlterPropGraphStmt *stmt)
 								   Anum_pg_propgraph_label_oid,
 								   ObjectIdGetDatum(pgrelid),
 								   CStringGetDatum(stmt->alter_label));
-		if (!labeloid)
-			ereport(ERROR,
-					errcode(ERRCODE_UNDEFINED_OBJECT),
-					errmsg("property graph \"%s\" element \"%s\" has no label \"%s\"",
-						   get_rel_name(pgrelid), stmt->element_alias, stmt->alter_label),
-					parser_errposition(pstate, -1));
-
-		ellabeloid = GetSysCacheOid2(PROPGRAPHELEMENTLABELELEMENTLABEL,
-									 Anum_pg_propgraph_element_label_oid,
-									 ObjectIdGetDatum(peoid),
-									 ObjectIdGetDatum(labeloid));
+		if (labeloid)
+			ellabeloid = GetSysCacheOid2(PROPGRAPHELEMENTLABELELEMENTLABEL,
+										 Anum_pg_propgraph_element_label_oid,
+										 ObjectIdGetDatum(peoid),
+										 ObjectIdGetDatum(labeloid));
 
 		if (!ellabeloid)
 			ereport(ERROR,
@@ -1688,21 +1676,24 @@ AlterPropGraph(ParseState *pstate, const AlterPropGraphStmt *stmt)
 		{
 			char	   *propname = strVal(lfirst(lc));
 			Oid			propoid;
-			Oid			plpoid;
+			Oid			plpoid = InvalidOid;
 
 			propoid = GetSysCacheOid2(PROPGRAPHPROPNAME,
 									  Anum_pg_propgraph_property_oid,
 									  ObjectIdGetDatum(pgrelid),
 									  CStringGetDatum(propname));
-			if (!propoid)
+			if (propoid)
+				plpoid = GetSysCacheOid2(PROPGRAPHLABELPROP,
+										 Anum_pg_propgraph_label_property_oid,
+										 ObjectIdGetDatum(ellabeloid),
+										 ObjectIdGetDatum(propoid));
+			if (!plpoid)
 				ereport(ERROR,
 						errcode(ERRCODE_UNDEFINED_OBJECT),
 						errmsg("property graph \"%s\" element \"%s\" label \"%s\" has no property \"%s\"",
 							   get_rel_name(pgrelid), stmt->element_alias, stmt->alter_label, propname),
 						parser_errposition(pstate, -1));
 
-			plpoid = GetSysCacheOid2(PROPGRAPHLABELPROP, Anum_pg_propgraph_label_property_oid, ObjectIdGetDatum(ellabeloid), ObjectIdGetDatum(propoid));
-
 			ObjectAddressSet(obj, PropgraphLabelPropertyRelationId, plpoid);
 			performDeletion(&obj, stmt->drop_behavior, 0);
 		}
diff --git a/src/test/regress/expected/create_property_graph.out b/src/test/regress/expected/create_property_graph.out
index 5930d844319..7f12697bbd5 100644
--- a/src/test/regress/expected/create_property_graph.out
+++ b/src/test/regress/expected/create_property_graph.out
@@ -89,6 +89,8 @@ CREATE PROPERTY GRAPH g4
     );
 ALTER PROPERTY GRAPH g4 ALTER VERTEX TABLE t2 ALTER LABEL t2 ADD PROPERTIES (k * 2 AS kk);
 ALTER PROPERTY GRAPH g4 ALTER VERTEX TABLE t2 ALTER LABEL t2 DROP PROPERTIES (k);
+ALTER PROPERTY GRAPH g4 ALTER VERTEX TABLE t2 ALTER LABEL t2 DROP PROPERTIES (yy);  -- error
+ERROR:  property graph "g4" element "t2" label "t2" has no property "yy"
 CREATE TABLE t11 (a int PRIMARY KEY);
 CREATE TABLE t12 (b int PRIMARY KEY);
 CREATE TABLE t13 (
diff --git a/src/test/regress/sql/create_property_graph.sql b/src/test/regress/sql/create_property_graph.sql
index a4285ef8846..171260ac69f 100644
--- a/src/test/regress/sql/create_property_graph.sql
+++ b/src/test/regress/sql/create_property_graph.sql
@@ -80,6 +80,7 @@ CREATE PROPERTY GRAPH g4
 
 ALTER PROPERTY GRAPH g4 ALTER VERTEX TABLE t2 ALTER LABEL t2 ADD PROPERTIES (k * 2 AS kk);
 ALTER PROPERTY GRAPH g4 ALTER VERTEX TABLE t2 ALTER LABEL t2 DROP PROPERTIES (k);
+ALTER PROPERTY GRAPH g4 ALTER VERTEX TABLE t2 ALTER LABEL t2 DROP PROPERTIES (yy);  -- error
 
 CREATE TABLE t11 (a int PRIMARY KEY);
 CREATE TABLE t12 (b int PRIMARY KEY);
-- 
2.34.1

