SUMMARY see $SUBJECT STEPS TO REPRODUCE 1. create tags with lots of photos on them on a slow disk with XMP sidecars enabled and lazy sync off (?) 2. merge these tags 3. while the sync process is running, merge two other tags OBSERVED RESULT Merged tags sometimes reappear with a couple of photos. EXPECTED RESULT Synced tags should never reappear. It is possible that the sync process updating the XMP sidecars is "overtaken" by a DB update process re-reading the XMP sidecars when the second merge process starts, and so ready old data? Maybe digikam should pause/postpone sync processes if conflicting reads/writes to not-yet-synced metadata can occur. But I can't prove that this is actually the root cause of what I observed, it's just a guess. ADDITIONAL INFORMATION KDE Neon 18.04 with all updates applied, Digikam appimage 6.1.0-git as of 20190403.
Git commit fd95ee87a298ebf230c728b96df59dca7d821521 by Maik Qualmann. Committed on 07/04/2019 at 20:03. Pushed by mqualmann into branch 'master'. check for running process FIXED-IN: 6.1.0 M +2 -2 NEWS M +14 -0 core/libs/album/manager/albummanager_talbum.cpp https://commits.kde.org/digikam/fd95ee87a298ebf230c728b96df59dca7d821521