Specifying engineering english via "//%" is not supported yet while using qsTrId()

If we use qsTrId() in a qml file - and try to specify the translatable content as below
//: This is the engineering description data - aka comment
//% "About Product"
text: qsTrId("qtn_prod_about_product")

The expectation is that the ts file generated using lupdate will have "About Product" inside the <source> tag.
Does not happen currently as expected.

The possible reason for the incorrect behaviour could be that the function call "msg.setSourceText(sourcetext);" is missing around line 234 in qdeclarative.cpp file.