Fix for HHH-11258

hibernate-core/src/main/antlr/sql-gen.g

@@ -28,7 +28,7 @@ options {
 	private StringBuilder buf = new StringBuilder();
 
 	private boolean captureExpression = false;
-	private StringBuilder expr = new StringBuilder();
+	protected java.util.List<StringBuilder> exprs = new java.util.ArrayList<StringBuilder>(java.util.Arrays.asList(new StringBuilder()));
 
 	protected void out(String s) {
 		getStringBuilder().append( s );
@@ -75,7 +75,7 @@ options {
 	}
 
 	protected StringBuilder getStringBuilder() {
-		return captureExpression ? expr : buf;
+		return captureExpression ? exprs.get(exprs.size() - 1) : buf;
 	}
 
 	protected void nyi(AST n) {
@@ -97,16 +97,27 @@ options {
 	}
 
 	protected void captureExpressionStart() {
+	    if ( captureExpression ) {
+            exprs.add( new StringBuilder() );
+	    } else {
 		    captureExpression = true;
 		}
+	}
 
 	protected void captureExpressionFinish() {
+	    // Capturing will only stop when we leave the last capture context
+	    if ( exprs.size() == 1 ) {
 		    captureExpression = false;
 		}
+	}
 
 	protected String resetCapture() {
-		final String expression = expr.toString();
+	    StringBuilder sb = exprs.remove( exprs.size() - 1 );
-		expr = new StringBuilder();
+		final String expression = sb.toString();
+		if ( exprs.isEmpty() ) {
+		    sb.setLength(0);
+		    exprs.add( sb );
+		}
 		return expression;
 	}
 

hibernate-core/src/main/java/org/hibernate/hql/internal/ast/SqlGenerator.java

@@ -102,8 +102,12 @@ public class SqlGenerator extends SqlGeneratorBase implements ErrorReporter {
 
 	@Override
 	protected void out(String s) {
+		if ( exprs.size() > 1 ) {
+			super.out( s );
+		} else {
 			writer.clause( s );
 		}
+	}
 
 	@Override
 	protected void out(AST n) {