Remove draft revisions when review is published

critiquebrainz/db/revision.py

@@ -230,3 +230,22 @@ def votes(revision_id):
             else:  # False = negative
                 revision_votes["negative"] += 1
     return revision_votes
+
+
+def delete_draft_revisons(review_id):
+    """Delete all draft revisions of a review after the review has been published.
+
+    Args:
+        review_id: ID of the review.
+    """
+    with db.engine.connect() as connection:
+        connection.execute(sqlalchemy.text("""
+            DELETE
+              FROM revision
+              USING review
+              WHERE review.id = revision.review_id
+              AND revision.review_id = :review_id
+              AND revision.timestamp < review.published_on               
+        """), {
+            "review_id": review_id,
+        })

critiquebrainz/frontend/views/review.py

@@ -417,6 +417,9 @@ def edit(id):
             raise BadRequest(lazy_gettext("Changing license of a published review\
                 or converting a published review back to drafts is not allowed."))
 
+        if form.state.data == "publish" and review["is_draft"] == True:
+            db_revision.delete_draft_revisons(review["id"])
+
         flash.success(gettext("Review has been updated."))
         return redirect(url_for('.entity', id=review["id"]))
     else: