Sync rule: update policy "ignore" removes undefined properties

[idandr]

Expected Behavior

With update policy "ignore", updates for the same host should be ignored.

Current Behavior

After an update from director 1.9.1 to 1.10.2 updates of host values (here: "address" not defined) are not ignored with update policy "ignore".

Possible Solution

May be a side effect of #2623, that fixes "merge" but effects "ignore"?

Steps to Reproduce (for bugs)

Have some newly undefined values in an existing hosts import. Set sync update policy to "ignore". Have a look at the sync preview - variables with undefined values would be removed.

Your Environment

• Director version (System - About): 1.10.2
• Icinga Web 2 version (System - About): 2.11.2

[Thomas-Gelf]

Note for myself -> branch fix/setting-null-with-merge