fetch streaming expression multiple collections problem

[uyilmaz <uy...@vivaldi.net.INVALID>]

Hello all,

When I try to use the "select" streaming expression with multiple collections it works without any problems, like:

search(
    "collection1,collection2",
    q="*:*",
    fl="field1,field2",
    qt="/export",
    sort="field1 desc"
)

but when I try to use the "fetch" expression similarly:

fetch(
    "collection1,collection2"
....

It gives me an error saying: "EXCEPTION": "java.io.IOException: Slices not found for \"collection1,collection2\""

when I use it without quotes problem is resolved but another problem arises:

fetch(
    collection1,collection2
....

which fetches fields only from collection1.. and returns empty for documents residing in collection2.

I took a look at the source code of fetch and select expressions, they both get collection parameter exactly the same way, using:

String collectionName = factory.getValueOperand(expression, 0)

I'm lost. When I use an alias in place of multiple collections it works as desired, but we have many collections and queries are generated dynamically so we would need many combination of aliases.

Need help.
Regards

-- 
uyilmaz <uy...@vivaldi.net>