I have the same issue. Changes get pushed to gerrit and rebased on the server. This is what I have, though not perfected yet.
prunable = "!f() { \
: git log ; \
target=\"$1\"; \
[ -z \"$target\" ] && target=$(git for-each-ref --format=\"%(refname:short)\" --count=1 refs/remotes/m/); \
if [ -z \"$target\" ]; then echo \"No remote branches found in refs/remotes/m/\"; return 1; fi; \
echo \"# git branch --merged shows merged if same commit ID only\" ;\
echo \"# if rebased, git cherry can show branch HEAD is merged\" ;\
echo \"# git log grep will check latest commit subject only. if amended, this status won't be accurate\" ;\
echo \"# Comparing against $target...\"; \
echo \"# git branch --merged:\"; \
git branch --merged $target ;\
echo \" ,- git cherry\" ; \
echo \" | ,- git log grep latest message\"; \
for branch in $(git for-each-ref --format='%(refname:short)' refs/heads/); do \
if git cherry \"$target\" \"$branch\" | tail -n 1 | grep -q \"^-\"; then \
cr=""; \
else \
cr=""; \
fi ; \
c=$(git rev-parse --short $branch) ; \
subject=$(git log -1 --format=%s \"$branch\" | sed 's/[][(){}.^$\*+?|\\/]/\\\\&/g') ; \
if git log --grep=\"^$subject$\" --oneline \"$target\" | grep -q .; then \
printf \"$cr $c %-20s $subject\\n\" $branch; \
else \
printf \"$cr \\033[0;33m$c \\033[0;32m%-20s\\033[0m $subject\\n\" $branch; \
fi; \
done; \
}; f"
(some emojis missing in above. see gist)
https://gist.github.com/lawm/8087252b4372759b2fe3b4052bf7e45...It prints the results of 3 methods:
1. git branch --merged
2. git cherry
3. grep upstream git log for a commit with the same commit subject
Has some caveats, like
if upstream's commit was amended or the actual code change is different, it can have a false positive, or
if there are multiple commits on your local branch, only the top commit is checked