Correct targets for pushing db artifact

Signed-off-by: Jan Lipovský <jlipovsk@redhat.com>

Author: lipoja

iib/workers/tasks/build_containerized_merge.py

@@ -111,6 +111,9 @@ def handle_containerized_merge_request(
     reset_docker_config()
     set_request_state(request_id, 'in_progress', 'Preparing request for merge')
 
+    if not target_index:
+        raise IIBError('target_index is required.')
+
     # Prepare request
     with set_registry_token(overwrite_target_index_token, target_index, append=True):
         prebuild_info = prepare_request_for_build(
@@ -151,7 +154,7 @@ def handle_containerized_merge_request(
             localized_git_catalog_path,
         ) = prepare_git_repository_for_build(
             request_id=request_id,
-            from_index=source_from_index,
+            from_index=target_index,
             temp_dir=temp_dir,
             branch=branch,
             index_to_gitlab_push_map=index_to_gitlab_push_map or {},
@@ -346,8 +349,8 @@ def handle_containerized_merge_request(
             # index.db file if the pipeline fails.
             original_index_db_digest = push_index_db_artifact(
                 request_id=request_id,
-                from_index=source_from_index,
-                index_db_path=source_index_db_path,
+                from_index=str(target_index),
+                index_db_path=str(target_index_db_path),
                 operators=operators_in_db,
                 overwrite_from_index=overwrite_target_index,
                 request_type='merge',
@@ -370,7 +373,7 @@ def handle_containerized_merge_request(
                 index_git_repo=index_git_repo,
                 overwrite_from_index=overwrite_target_index,
                 request_id=request_id,
-                from_index=source_from_index,
+                from_index=target_index,
                 index_repo_map={},
                 original_index_db_digest=original_index_db_digest,
                 reason=f"error: {e}",