From 7b064afbd33729ae15d06aba1bdb5cf17b2d5dca Mon Sep 17 00:00:00 2001
From: Christian Beikov <christian.beikov@gmail.com>
Date: Thu, 30 Jan 2020 06:31:42 +0100
Subject: [PATCH] Use type inference for every added when/otherwise arm for
 case expressions

---
 .../sqm/tree/expression/SqmCaseSearched.java   | 18 ++++++++++++++++--
 .../sqm/tree/expression/SqmCaseSimple.java     | 18 ++++++++++++++++--
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSearched.java b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSearched.java
index a07591fbdf..2c79537bbe 100644
--- a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSearched.java
+++ b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSearched.java
@@ -12,6 +12,7 @@ import javax.persistence.criteria.Expression;
 
 import org.hibernate.query.criteria.JpaExpression;
 import org.hibernate.query.criteria.JpaSearchedCase;
+import org.hibernate.query.internal.QueryHelper;
 import org.hibernate.query.sqm.NodeBuilder;
 import org.hibernate.query.sqm.SqmExpressable;
 import org.hibernate.query.sqm.SemanticQueryWalker;
@@ -45,12 +46,25 @@ public class SqmCaseSearched<R>
 
 	public void when(SqmPredicate predicate, SqmExpression<R> result) {
 		whenFragments.add( new WhenFragment<>( predicate, result ) );
-		applyInferableType( result.getNodeType() );
+		applyInferableResultType( result.getNodeType() );
 	}
 
 	public void otherwise(SqmExpression<R> otherwiseExpression) {
 		this.otherwise = otherwiseExpression;
-		applyInferableType( otherwiseExpression.getNodeType() );
+		applyInferableResultType( otherwiseExpression.getNodeType() );
+	}
+
+	private void applyInferableResultType(SqmExpressable<?> type) {
+		if ( type == null ) {
+			return;
+		}
+
+		final SqmExpressable<?> oldType = getNodeType();
+
+		final SqmExpressable<?> newType = QueryHelper.highestPrecedenceType2( oldType, type );
+		if ( newType != null && newType != oldType ) {
+			internalApplyInferableType( newType );
+		}
 	}
 
 	@Override
diff --git a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSimple.java b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSimple.java
index a6e433909a..f1dbbd1a5a 100644
--- a/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSimple.java
+++ b/hibernate-core/src/main/java/org/hibernate/query/sqm/tree/expression/SqmCaseSimple.java
@@ -13,6 +13,7 @@ import javax.persistence.criteria.Expression;
 
 import org.hibernate.query.criteria.JpaExpression;
 import org.hibernate.query.criteria.JpaSimpleCase;
+import org.hibernate.query.internal.QueryHelper;
 import org.hibernate.query.sqm.NodeBuilder;
 import org.hibernate.query.sqm.SqmExpressable;
 import org.hibernate.query.sqm.SemanticQueryWalker;
@@ -52,13 +53,26 @@ public class SqmCaseSimple<T,R>
 	public void otherwise(SqmExpression<R> otherwiseExpression) {
 		this.otherwise = otherwiseExpression;
 
-		applyInferableType( otherwiseExpression.getNodeType() );
+		applyInferableResultType( otherwiseExpression.getNodeType() );
 	}
 
 	public void when(SqmExpression<T> test, SqmExpression<R> result) {
 		whenFragments.add( new WhenFragment<>( test, result ) );
 
-		applyInferableType( result.getNodeType() );
+		applyInferableResultType( result.getNodeType() );
+	}
+
+	private void applyInferableResultType(SqmExpressable<?> type) {
+		if ( type == null ) {
+			return;
+		}
+
+		final SqmExpressable<?> oldType = getNodeType();
+
+		final SqmExpressable<?> newType = QueryHelper.highestPrecedenceType2(oldType, type );
+		if ( newType != null && newType != oldType ) {
+			internalApplyInferableType( newType );
+		}
 	}
 
 	@Override