Handle already queued PRs

maintenance/code-backports.sh

@@ -49,17 +49,21 @@ git checkout $beQuiet v$version-next-backports 2>/dev/null &&
     git fetch $beQuiet --all &&
     git pull $beQuiet origin v$version-next-backports &&
     git rebase origin/v$version 2>/dev/null &&
-    git push -u origin v$version-next-backports|| abortAndExit rebase
+    git push -u origin +v$version-next-backports || abortAndExit rebase
 
 # Find backports to attempt:
 prlist=`gh pr list -L 1 --repo squid-cache/squid --state closed --label backport-to-v$version | wc -l`
 if test "$prlist" -ne 0; then
   gh pr list --repo squid-cache/squid --state closed --label backport-to-v$version | while read prnum text; do
     # find a commit in $srcbranch with " (#$prnum)" subject suffix
     git log --oneline github/$srcbranch --grep=" (#$prnum)\$" | while read sha rest; do
-      msg=`git cherry-pick $sha || abortAndContinue cherry-pick`
-      if ! test -z $msg ; then
+      msg=`git cherry-pick $beQuiet $sha 2>&1 || abortAndContinue cherry-pick`
+      if ! test -z "$msg" ; then
         echo $msg | grep -E "^error:"
+        if `echo $msg | grep "The previous cherry-pick is now empty"`; then
+            gh pr edit $prnum --remove-label backport-to-v$version
+            gh pr comment $prnum --body "queued for backport to v$version"
+        fi
       fi
       gitCleanWorkspace
     done