extending doesn't work when using a variable as class name

[eladchen]

Here's a short code to trigger the behavior i'm referring to

This works:

.example {
    .table-pagination {
        float: right;
    }
    .table-length:extend(.example .table-pagination) {}
}

This doesn't:

@classname: test;
.@{classname} {
    .table-pagination {
        float: right;
    }

    .table-length:extend(.@{classname} .table-pagination) {}
}

Doesn't work even if @{classname} is with the actual class name - "test"

...Is this the expected behavior ?

[seven-phases-max]

...Is this the expected behavior ?

Yes. See http://lesscss.org/features/#extend-feature-selector-interpolation-with-extend.

[seven-phases-max]

Closing as duplicate of #1539.