Not sure if this is a bug or expected behaviour, but its a bit confusing.

If I call the notifyCommit URL without a sha1, then the build only triggers if 'scm polling' is enabled. However, if a sha1 is provided then the build triggers regardless.

I realise that when the sha1 is provided, strictly speaking this isn't 'polling' happening. However this means that the only way to disable triggering (eg for a nightly sonar build) is to enable the scm trigger, set no time and then select the "Ignore post-commit hooks" option. ie:

• polling disabled - triggers if and only if a sha1 was provided
• polling enabled - triggers
• polling enabled but skipped - doesn't trigger

this is a but unintuitive and confusing. The git plugin should require that polling is enabled (even with an empty time), just like it does if a sha1 isn't provided.