[UNDERTOW-2146] At Validator, process partial scriptlet only if value…

[fl4via]

… is not an EL expression

Signed-off-by: Flavia Rainone frainone@redhat.com

[fl4via]

@rmartinc can you please review? I couldn't add a test because the tests that are there do not cause invocation of Validator

[rmartinc]

Hi @fl4via!

As we have been talking internally the scriptlet expression when used inside a JSP tag attribute should be the full value. It cannot be used partially inside a tag attribute. The spec in the chapter Request Time Attribute Values says:

When using scriptlet expressions, the expression must appear by itself (multiple expressions, and mixing of expressions and string constants are not permitted).

And checking the grammar:

Attribute ::= Name Eq ( ( '"<%=' RTAttributeValueDouble ) | ( "'<%=" RTAttributeValueSingle ) | ( '"' AttributeValueDouble ) | ( "'" AttributeValueSingle ) )

RTAttributeValueDouble ::= ( ( QuotedChar - '"' ) - ( ( QuotedChar - '"' ) '%>' ) ) ( '%>"' | ) [ vc: RTAttributeScriptingEnabled ] [ vc: ExpressionBodyContent ]

RTAttributeValueSingle ::= ( ( QuotedChar - "'" ) - ( ( QuotedChar - "'" ) '%>' ) ) ( "%>'" | ) [ vc: RTAttributeScriptingEnabled ] [ vc: ExpressionBodyContent ]

So the attribute value, if using scriptlet, should start by <%= and finish by %> and cannot mix strings like EL expressions do. The spec is the same in previous 2.3 and 3.0 versions.

I would close this PR as UNDERTOW-2146 is not a bug. UNDERTOW-1319 is not a bug either and, I don't know if it's late, but I would revert that change if possible.

[fl4via]

Thank you for the feedback @rmartinc ! I'll do as you say and check if it is possible to revert UNDERTOW-1319.

[ropalka]

This PR have been superseded with https://github.com/undertow-io/jastow/pull/78