From 4ff3dd5579ebe5f9c5e4328b8e457365f1f0aed6 Mon Sep 17 00:00:00 2001
From: Gerrit Meier <meistermeier@gmail.com>
Date: Wed, 18 Dec 2024 10:37:55 +0100
Subject: [PATCH] fix: Fix scoping issue with existential subquery (#1151)

Remove elements from scope cache when leaving existential subquery.

Closes #1147
---
 .../neo4j/cypherdsl/parser/ComparisonIT.java  | 42 +++++++++++++++++++
 .../core/internal/ScopingStrategy.java        |  6 ++-
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/neo4j-cypher-dsl-parser/src/test/java/org/neo4j/cypherdsl/parser/ComparisonIT.java b/neo4j-cypher-dsl-parser/src/test/java/org/neo4j/cypherdsl/parser/ComparisonIT.java
index 633c6cb4f4..ed4d636315 100644
--- a/neo4j-cypher-dsl-parser/src/test/java/org/neo4j/cypherdsl/parser/ComparisonIT.java
+++ b/neo4j-cypher-dsl-parser/src/test/java/org/neo4j/cypherdsl/parser/ComparisonIT.java
@@ -728,4 +728,46 @@ static boolean areSemanticallyEquivalent(Statement statement1, Map<String, Objec
 
 		return true;
 	}
+
+	@Test // GH-1147
+	void shouldNotRecognizeLocallyScopedElementsFromExistentialSubqueries() {
+		var cypher = """
+		MATCH (this:Series)
+		WHERE ((EXISTS {
+		MATCH (this)-[edge:MANUFACTURER]->(this0:Manufacturer)
+			WHERE (this0.name = $param0 AND edge.current = $param1)
+		}
+		OR EXISTS {
+			MATCH (this)-[edge:MANUFACTURER]->(this1:Manufacturer)
+			WHERE (this1.name = $param2 AND edge.current = $param3)
+		})
+		AND EXISTS {
+			MATCH (this)-[edge:BRAND]->(this2:Brand)
+			WHERE (this2.name = $param4 AND edge.current = $param5)
+		})
+		RETURN this""";
+		var renderer = Renderer.getRenderer(Configuration.newConfig()
+			.withPrettyPrint(true)
+			.withGeneratedNames(true)
+			.build());
+		var normalized = renderer.render(CypherParser.parse(cypher));
+		assertThat(normalized).isEqualTo("""
+		MATCH (v0:Series)
+		WHERE ((EXISTS {
+		      MATCH (v0)-[v1:MANUFACTURER]->(v2:Manufacturer)
+		      WHERE (v2.name = $p0
+		        AND v1.current = $p1)
+		    }
+		    OR EXISTS {
+		      MATCH (v0)-[v1:MANUFACTURER]->(v2:Manufacturer)
+		      WHERE (v2.name = $p2
+		        AND v1.current = $p3)
+		    })
+		  AND EXISTS {
+		    MATCH (v0)-[v1:BRAND]->(v2:Brand)
+		    WHERE (v2.name = $p4
+		      AND v1.current = $p5)
+		  })
+		RETURN v0""");
+	}
 }
diff --git a/neo4j-cypher-dsl/src/main/java/org/neo4j/cypherdsl/core/internal/ScopingStrategy.java b/neo4j-cypher-dsl/src/main/java/org/neo4j/cypherdsl/core/internal/ScopingStrategy.java
index 2e50301cef..7be901e458 100644
--- a/neo4j-cypher-dsl/src/main/java/org/neo4j/cypherdsl/core/internal/ScopingStrategy.java
+++ b/neo4j-cypher-dsl/src/main/java/org/neo4j/cypherdsl/core/internal/ScopingStrategy.java
@@ -42,6 +42,7 @@
 import org.neo4j.cypherdsl.core.AliasedExpression;
 import org.neo4j.cypherdsl.core.Asterisk;
 import org.neo4j.cypherdsl.core.Cypher;
+import org.neo4j.cypherdsl.core.ExistentialSubquery;
 import org.neo4j.cypherdsl.core.Expression;
 import org.neo4j.cypherdsl.core.Foreach;
 import org.neo4j.cypherdsl.core.FunctionInvocation;
@@ -259,7 +260,10 @@ public void doLeave(Visitable visitable) {
 			leaveStatement(visitable);
 		} else if (hasLocalScope(visitable)) {
 			notify = true;
-			this.dequeOfVisitedNamed.pop();
+			Set<IdentifiableElement> lastVisitedNames = this.dequeOfVisitedNamed.pop();
+			if (visitable instanceof ExistentialSubquery) {
+				this.afterStatement.retainAll(lastVisitedNames);
+			}
 		} else {
 			clearPreviouslyVisitedNamed(visitable);
 		}