scripts: Add logic for handling common merge conflicts

Signed-off-by: timflannagan <[email protected]>

Author: timflannagan

scripts/sync_pop_candidate.sh

@@ -1,7 +1,5 @@
 #!/usr/bin/env bash
 
-cph=$(git rev-list -n 1 CHERRY_PICK_HEAD 2> /dev/null)
-
 set -o errexit
 set -o pipefail
 
@@ -36,20 +34,44 @@ function pop() {
     fi
     printf 'popping: %s\n' "${rc}"
 
-    if [[ ! $cph ]]; then
-        git cherry-pick --allow-empty --keep-redundant-commits -Xsubtree="${subtree_dir}" "${rc}"
-    else
-        if [[ $cph != "${rc}" ]]; then
-            printf 'unexpected CHERRY_PICK_HEAD:\ngot %s\nexpected: %s\n' "${cph}" "${rc}"
-            exit
-        fi
-        printf 'cherry-pick in progress for %s\n' "${cph}"
-        git add .
+    # Note: this may require a more up-to-date git version
+    if ! git cherry-pick --allow-empty --keep-redundant-commits -Xsubtree="${subtree_dir}" "${rc}"; then
+        # Always blast away the vendor directory given OLM/registry still commit it into source control.
+        git rm -rf "${subtree_dir}"/vendor 2>/dev/null || true
+
+        # TODO: handle the case where there's a single merge conflict.
+        # TODO: handle root go.mod merge conflicts!
+        # TODO: maybe use a while loop here?
+        # TODO: verify there's no remaining merge conflicts
+        num_conflicts=$(git diff --name-only --diff-filter=U --relative | wc -l)
+        while [[ $num_conflicts != 0 ]] ; do
+            file=$(git diff --name-only --diff-filter=U --relative)
+
+            if [[ $file == *"go.mod"* ]]; then
+                git diff "${subtree_dir}"/go.mod
+
+                git checkout --theirs "${subtree_dir}"/go.mod
+                pushd "${subtree_dir}"
+                # Note: handle case where this fails. does this update the root module too?
+                go mod tidy
+                # TODO: double-check there's no remaining markers via git diff --check: <https://stackoverflow.com/questions/3065650/whats-the-simplest-way-to-list-conflicted-files-in-git>?
+                git add go.mod go.sum
+                popd
+            else
+                git checkout --theirs "$file"
+                git diff "$file"
+                git add "$file"
+            fi
+
+            num_conflicts=$(git diff --name-only --diff-filter=U --relative | wc -l)
+            echo "number of merge conflicts remaining: $num_conflicts"
+        done
 
         if [[ -z $(git status --porcelain) ]]; then
             git commit --allow-empty
         else
-            git cherry-pick --continue
+            echo "Current cherry pick status: $(git status --porcelain)"
+            git -c core.editor=true cherry-pick --continue
         fi
     fi