Some tests hang on OS X

This issue was created automatically from an original Mantis Issue. Further discussion may take place here.

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Some pq tests hang on OS X. Usually, when a pop-up menu or dialog is up. See for example pqClient3DWidgetInCustomFilter. See the attached stack trace. Here is a list of tests that fail this way:

    149 - pqClient3DWidgetInCustomFilter (Failed)
    150 - pqClientCalculator (Failed)
    155 - pqClientContourRange (Failed)
    157 - pqClientCreateSourceWithoutConnect (Failed)
    159 - pqClientCut (Failed)
    160 - pqClientCutMulti (Failed)
    161 - pqClientExodusPanel (Failed)
    163 - pqClientLoadStateSelection (Failed)
    166 - pqClientOpenSaveData (Failed)
    167 - pqClientRepresentationSelector (Failed)
    168 - pqClientSelectionUndo (Failed)
    169 - pqClientSimpleInteraction (Failed)
    170 - pqClientStreamTracer (Failed)
    171 - pqClientStreamTracerUpdates (Failed)
    172 - pqClientSubMenu (Failed)
    173 - pqClientThreshold (Failed)
    176 - pqClientViewSettingsDialog (Failed)