fix(hack): various fixes & improvements to cherry-pick script (#12714)

(cherry picked from commit 7ba20fe)

docs/releasing.md

@@ -7,10 +7,10 @@
 Then get a list of commits you may want to cherry-pick:
 
 ```bash
-./hack/cherry-pick.sh release-3.3 "fix" true
-./hack/cherry-pick.sh release-3.3 "chore(deps)" true
-./hack/cherry-pick.sh release-3.3 "build" true
-./hack/cherry-pick.sh release-3.3 "ci" true
+./hack/cherry-pick.sh release-3.3 "fix"
+./hack/cherry-pick.sh release-3.3 "chore(deps)"
+./hack/cherry-pick.sh release-3.3 "build"
+./hack/cherry-pick.sh release-3.3 "ci"
 ```
 
 To automatically cherry-pick, run the following:

hack/cherry-pick.sh

@@ -1,46 +1,56 @@
 #!/usr/bin/env bash
 set -eu
-# See docs/releasing.md for instructions.
+# See ../docs/releasing.md for instructions.
 
-br="$1" # branch name, e.g. release-3.3
+branch="$1" # branch name, e.g. release-3.3
 commitPrefix="$2" # prefix to use to filter commits, e.g. fix, chore(deps), build, ci
-# whether this is dry-run. If set to `true`, this script will only print out the list
-# of commits. Otherwise, this script will automatically cherry-pick the commits to the branch.
-dryRun="$3"
+# If dryRun is unset or `true`, only print the list of commits to be cherry-picked.
+# Otherwise, cherry-pick the commits to the specified branch.
+dryRun="${3:-"true"}"
+
+# unfortunately, cherry-picking to another branch is not possible, so error out if not on the branch (c.f. https://stackoverflow.com/q/13878904/3431180)
+curr_branch=$(git rev-parse --abbrev-ref HEAD)
+if [[ "$curr_branch" != "$branch" ]]; then
+  echo "Current branch is '$curr_branch', but trying to cherry-pick to branch '$branch'. You must have branch '$branch' checked out in order to cherry-pick"
+  exit 1
+fi
 
 commitGrepPattern="^${commitPrefix}(*.*)*:.*(#"
 
 # find the branch point
-base=$(git merge-base "$br" main)
+base=$(git merge-base "$branch" main)
 
 # extract the PRs from stdin
-prNo() {
-  set -eu
+getPRNum() {
   cat | sed "s|.*(\(#[0-9]*\))|\1|"
 }
 
 # list the PRs on each branch
-prs() {
-  set -eu
-  git log --format="%s" --grep "${commitGrepPattern}" "$1...$2" | prNo | sort > "/tmp/$2"
+getPRs() {
+  git log --format="%s" --grep "${commitGrepPattern}" "$1...$2" | getPRNum | sort > "/tmp/$2"
 }
 
-prs "$base" "$br"
-prs "$base" main
+getPRs "$base" "$branch"
+getPRs "$base" main
 
 # find PRs added to main
-diff "/tmp/$br" /tmp/main | grep "^> " | cut -c 3- > /tmp/prs
+diff "/tmp/$branch" /tmp/main | grep "^> " | cut -c 3- > /tmp/prs
 
 # print all the commits that need cherry-picking
-git log --oneline --grep "${commitGrepPattern}" "$base...main" | while read -r m; do
+git log --oneline --grep "${commitGrepPattern}" "$base...main" | tac | while read -r m; do
+  if ! grep -q "$(echo "$m" | getPRNum)" /tmp/prs ; then
+    continue
+  fi
+
   if [[ "$dryRun" == "true" ]]; then
-    grep -q "$(echo "$m" | prNo)" /tmp/prs && echo "$m"
-  else
-    commit=$(grep -q "$(echo "$m" | prNo)" /tmp/prs && echo "${m:0:9}")
-    echo "cherry-picking: $commit"
-    if ! git cherry-pick "$commit"; then
-      echo "failed to cherry-pick $commit"
-      git cherry-pick --abort
-    fi
+    echo "$m"
+    continue
+  fi
+
+  commit=${m:0:9}
+  echo "cherry-picking: $commit"
+  if ! git cherry-pick "$commit" -x -Xpatience ; then
+    echo "failed to cherry-pick $commit"
+    git cherry-pick --abort
   fi
 done