merge proposals do not show whitespace changes

When adding or removing whitespaces with a git merge proposal, the diff does show that a line changed. but it does not show what changed if the changes were only about whitespaces.

You have to mark the lines with the mouse as a workaround to see the change.

See eg. https://code.launchpad.net/~powersj/cloudware/+git/cpc_jenkins/+merge/402450 for an example where this happens (line 239 240 for file jenkins/jobs/gcp.yaml )

In general it would be useful to make whitespaces visible so also for new files, whitespaces would be visible.