In one specific situation the Hibernate fails to parse the JPQL query correctly. When there is "select" query with "left outer join" with "select size" on join part - the hiberante falls with "String index out of range: -5" exception.

I first encountered this with MSSQL database, and then succesfully reproduced the bug with HSQL database. I will attach to this issue a simple maven project that reproduces this bug.

The JPQL query, that makes hibernate fall looks like this:
"Select a, b.size from EntityA a left outer join a.entityBList b";

Strangely, if you change in that query "left outer join" to "join", it Hibernate stops from falling with exception.

Here is full stacktrace:

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: -5
at java.lang.String.substring(String.java:1875)
at org.hibernate.hql.internal.CollectionSubqueryFactory.createCollectionSubquery(CollectionSubqueryFactory.java:52)
at org.hibernate.hql.internal.ast.tree.FromElementType.toColumns(FromElementType.java:400)
at org.hibernate.hql.internal.ast.tree.FromElementType.toColumns(FromElementType.java:382)
at org.hibernate.hql.internal.ast.tree.FromElement.toColumns(FromElement.java:504)
at org.hibernate.hql.internal.ast.tree.DotNode.getColumns(DotNode.java:139)
at org.hibernate.hql.internal.ast.tree.DotNode.initText(DotNode.java:261)
at org.hibernate.hql.internal.ast.tree.DotNode.resolve(DotNode.java:255)
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:126)
at org.hibernate.hql.internal.ast.tree.FromReferenceNode.resolve(FromReferenceNode.java:121)
at org.hibernate.hql.internal.ast.tree.DotNode.resolveSelectExpression(DotNode.java:711)
at org.hibernate.hql.internal.ast.HqlSqlWalker.resolveSelectExpression(HqlSqlWalker.java:957)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExpr(HqlSqlBaseWalker.java:2248)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectExprList(HqlSqlBaseWalker.java:2185)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectClause(HqlSqlBaseWalker.java:1471)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:571)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:278)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:206)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:158)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:126)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:88)
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:190)
at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:301)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:236)
at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1796)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:328)