Comment 1 for bug 1635087

Looks like clearing via the X is equivalent to changing the search query 5 times:

Debug [Main]: WSearchLineEdit::onSearchTextCleared
Debug [Main]: WSearchLineEdit::slotTextChanged ""
Debug [Main]: WSearchLineEdit::triggerSearch ""
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 2 ms 293
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 2 ms 293
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 2 ms 293
Debug [Main]: WSearchLineEdit::triggerSearch ""
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 3 ms 293
Debug [Main]: LibraryTableModel(0x7fafcfbf9600) select() took 3 ms 293

Other than a few minor differences the code paths are identical (e.g. restoring the vertical bar position) so we can probably fix this by making it search for "" just once.

Odd that the workaround works, because it's functionally equivalent except for:

- QLineEdit::clear()

- WTrackTableView::restoreVScrollVarPosition() [1]

Compare the WTrackTableView::onSearchCleared vs. WTrackTableView::onSearch

-

[1] https://github.com/mixxxdj/mixxx/blob/master/src/widget/wtracktableview.cpp#L981