fix(ci): handle merge commits in welan cherry-pick

Replace the manual commit-accumulation loop with a two-phase approach:
1. Walk first-parent to locate the upstream boundary (unchanged logic).
2. Use `git log --no-merges --reverse` over that range to collect only
   cherry-pickable, non-merge commits.

Previously, a merge commit at the tip (e.g. from a merged PR) caused
`git cherry-pick` to fail with "is a merge but no -m option was given".
The new approach surfaces the real patch commits from all merged branches
instead, so no -m is ever needed.

Author: weizhoublue

.github/workflows/a-welan-release.yml

@@ -89,31 +89,42 @@ jobs:
         id: patches
         continue-on-error: true
         run: |
-          patch_commits=()
-          ref="origin/welan"
-
+          # Walk the first-parent chain to find the upstream boundary: the first
+          # commit NOT authored by WELAN_PATCH_AUTHOR. Merge commits count as
+          # authored by whoever merged them, so this correctly stops at the
+          # upstream base even when the tip is a merge commit.
+          base_ref="origin/welan"
           while true; do
-            author="$(git log -1 --format='%an' "$ref")"
+            author="$(git log -1 --format='%an' "$base_ref")"
             if [[ "$author" != *"$WELAN_PATCH_AUTHOR"* ]]; then
               break
             fi
-
-            patch_commits=("$ref" "${patch_commits[@]}")
-
-            if ! git rev-parse "${ref}^" >/dev/null 2>&1; then
+            if ! git rev-parse "${base_ref}^" >/dev/null 2>&1; then
               break
             fi
-            ref="${ref}^"
+            base_ref="${base_ref}^"
           done
 
-          if [ "${#patch_commits[@]}" -eq 0 ]; then
+          if [[ "$(git rev-parse "$base_ref")" == "$(git rev-parse "origin/welan")" ]]; then
             echo "::error::No commits authored by $WELAN_PATCH_AUTHOR found at the tip of origin/welan"
             exit 1
           fi
 
+          # Collect all non-merge commits in the weizhoublue range (oldest first).
+          # --no-merges skips merge bookkeeping commits and instead surfaces the
+          # real patch commits from any merged branches, making each entry safely
+          # cherry-pickable without needing -m.
+          mapfile -t patch_commits < <(
+            git log --no-merges --reverse --format='%H' "${base_ref}..origin/welan"
+          )
+
+          if [ "${#patch_commits[@]}" -eq 0 ]; then
+            echo "::error::No non-merge commits found between $base_ref and origin/welan"
+            exit 1
+          fi
+
           echo "Cherry-picking ${#patch_commits[@]} commit(s) from origin/welan (author: $WELAN_PATCH_AUTHOR)"
-          for commit in "${patch_commits[@]}"; do
-            sha="$(git rev-parse "$commit")"
+          for sha in "${patch_commits[@]}"; do
             subject="$(git log -1 --format='%s' "$sha")"
             echo "Cherry-picking $sha $subject"
             git cherry-pick "$sha"