In https://codereview.chromium.org/2887993003/ , code has been added to display an empty cert selection box on the wifi config dialog if
- a ClientCertPattern is set by policy for the network
- no client cert has been selected by it.

Wrong behavior:
However, now it's possible to connect to a network in this state (empty box displayed), Chrome OS will use the first of the user's certificate certiifcates.

Expected behavior:
It should not be possible to connect to a network which has a ClientCertPattern and no matching client cert could be selected.

This made analysis of  bug 788655  more cubersome.