Fix DB2 10.5 testsuite issues

hibernate-community-dialects/src/main/java/org/hibernate/community/dialect/DB2LegacySqlAstTranslator.java

@@ -420,7 +420,7 @@ public class DB2LegacySqlAstTranslator<T extends JdbcOperation> extends Abstract
 						break;
 				}
 			}
-			renderComparisonEmulateDecode( lhs, operator, rhs );
+			renderComparisonEmulateDecode( lhs, operator, rhs, SqlAstNodeRenderingMode.NO_UNTYPED );
 		}
 	}
 

hibernate-core/src/main/java/org/hibernate/dialect/DB2Dialect.java

@@ -862,7 +862,7 @@ public class DB2Dialect extends Dialect {
 
 	@Override
 	public boolean supportsIsTrue() {
-		return true;
+		return getDB2Version().isSameOrAfter( 11 );
 	}
 
 	@Override

hibernate-core/src/main/java/org/hibernate/dialect/DB2SqlAstTranslator.java

@@ -444,7 +444,7 @@ public class DB2SqlAstTranslator<T extends JdbcOperation> extends AbstractSqlAst
 						break;
 				}
 			}
-			renderComparisonEmulateDecode( lhs, operator, rhs );
+			renderComparisonEmulateDecode( lhs, operator, rhs, SqlAstNodeRenderingMode.NO_UNTYPED );
 		}
 	}
 

hibernate-core/src/main/java/org/hibernate/sql/ast/spi/AbstractSqlAstTranslator.java

@@ -3625,17 +3625,25 @@ public abstract class AbstractSqlAstTranslator<T extends JdbcOperation> implemen
 	}
 
 	protected void renderComparisonEmulateDecode(Expression lhs, ComparisonOperator operator, Expression rhs) {
+		renderComparisonEmulateDecode( lhs, operator, rhs, SqlAstNodeRenderingMode.DEFAULT );
+	}
+
+	protected void renderComparisonEmulateDecode(
+			Expression lhs,
+			ComparisonOperator operator,
+			Expression rhs,
+			SqlAstNodeRenderingMode firstArgRenderingMode) {
 		switch ( operator ) {
 			case DISTINCT_FROM:
 				appendSql( "decode(" );
-				lhs.accept( this );
+				render( lhs, firstArgRenderingMode );
 				appendSql( ',' );
 				rhs.accept( this );
 				appendSql( ",0,1)=1" );
 				break;
 			case NOT_DISTINCT_FROM:
 				appendSql( "decode(" );
-				lhs.accept( this );
+				render( lhs, firstArgRenderingMode );
 				appendSql( ',' );
 				rhs.accept( this );
 				appendSql( ",0,1)=0" );