From 85de3fc21cd3678a5c328e6e6375b37731d0df99 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 v20260619 03/11] 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 62f91a08410..8868bd7576a 100644
--- a/src/backend/commands/propgraphcmds.c
+++ b/src/backend/commands/propgraphcmds.c
@@ -1580,7 +1580,7 @@ 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);
@@ -1591,17 +1591,11 @@ 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),
@@ -1622,7 +1616,7 @@ 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)
@@ -1634,17 +1628,11 @@ 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,
@@ -1657,21 +1645,24 @@ 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 e074c3cbd69..a1cf6e0f0b3 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 b10d7191506..3b27d4170bb 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

