tree e00815858101c7af604341f6e32b07ee4706a4b9
parent f2f136ffe975cae93aac627929ba72ff013a1b42
author Youssef Elghareeb <ghareeb@google.com> 1647281741 +0100
committer Youssef Elghareeb <ghareeb@google.com> 1649943144 +0000

ChangeUpdate: fix updating change meta ref when the update is no/op

There was a bug in RemoveAttentionSetOp in the sense that it always
returned true signalling to callers to perform an update regardless of
whether the attention set will get updated or not.

At the time we build the change meta ref commit, we append all updates
to the commit message. The method ChangeUpdate#isEmpty checks if there
are no updates and bails out at [1]. Sometimes the variable
plannedAttentionSetUpdates contained some updates, but this variable is
processed in [2] while writing the commit message and in some cases no
updates are written after all. This triggered the creation of a new
commit in the change meta ref which is redundant, hence fixing in this
change and adapting the test in PostReviewIT to ensure the change meta
ref is not updated in this case.

We fix this by factoring out plannedAttentionSetUpdates from #isEmpty
and explicitly checking that [2] did not include any attention set
updates. We do that because #isEmpty is also called from [3] in
AbstractChangeUpdate#apply (at the beginning of the processing) and it
bails out quickly if plannedAttentionSetUpdates is null.

[1]
https://gerrit.googlesource.com/gerrit/+/23678de2cdc56b676fcd80ea5d76b10af8c77304/java/com/google/gerrit/server/notedb/ChangeUpdate.java#1085

[2]
https://gerrit.googlesource.com/gerrit/+/23678de2cdc56b676fcd80ea5d76b10af8c77304/java/com/google/gerrit/server/notedb/ChangeUpdate.java#984

[3]
https://gerrit.googlesource.com/gerrit/+/23678de2cdc56b676fcd80ea5d76b10af8c77304/java/com/google/gerrit/server/notedb/AbstractChangeUpdate.java#220

Release-Notes: skip
Google-Bug-Id: b/221124220
Change-Id: I4086c614ff670e3bc43f772c3d004c65477db4eb
(cherry picked from commit ecf033e5ef52eab3b0a8d4d6aef9d2799a467020)