Example below shows the output from a sync with unshelve.

SCM Task: syncing files at change: 74939
... sync /var/lib/jenkins/workspace/__l1phy_int_mlb_10/...@74939
... force update false
... bypass have false
... duration: (226ms)
SCM Task: unshelve review: 61023
... sync /var/lib/jenkins/workspace/__l1phy_int_mlb_10/...
... unshelve -f -s 61023 /var/lib/jenkins/workspace/__l1phy_int_mlb_10/...
... revert -k /var/lib/jenkins/workspace/__l1phy_int_mlb_10/...
... duration: 0m 1s
Calculating built changes...
listing changes: //__l1phy_int_mlb_10_jenkins_p4_mlb-gb-mlb-pm-001/...@61023,74939

looking at the changes generated something seems wrong.
The changes needs to be
the last sync version to the latest sync
+the changes in the shelve

From the log it looks as if the changes are calculated between the shelved cl and the latest sync