EL 3 LambdaExpression failing with an exception irreversibly pollutes
variable scope
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Key: JBEE-158
URL:
https://issues.jboss.org/browse/JBEE-158
Project: JBoss Enterprise Spec APIs
Issue Type: Bug
Components: jboss-el-api
Affects Versions: jboss-el-api_3.0_spec-1.0.2.Final
Reporter: Paul Pogonyshev
Assignee: Tomaž Cerar
Priority: Major
Labels: el-expresion, patch
Fix For: jboss-el-api_3.0_spec-1.0.6.Final
Attachments: lambda-expression-scoping-fix.diff
When a lambda expression is exited with an exception, its variables are left on stack and
cannot be removed from it without hacks. My usecase is a customly defined function that
uses exceptions as means of non-local exit, but the bug triggers even without custom
functions, as demonstrated below.
Test case:
{noformat}
ELProcessor processor = new ELProcessor ();
processor.defineBean ("x", null);
try {
processor.eval ("(x -> x.bug ()) ('bug')");
}
catch (RuntimeException exception) {
// This is expected, there is no method bug() on strings.
}
processor.eval ("x"); // This must evaluate to null, but instead
evaluates to "bug".
{noformat}
Proposed fix will be attached as a short patch against
'javax/el/LambdaExpression.java'.