fix(pull): keep review body in sync when its comment is edited (#40058) (#40133)

Backport #40058 by @silverwind

A review's text is stored on both the review and its timeline comment,
but editing it in the web UI or through the issue comment API only
updated the comment. The reviews API kept returning the old body
afterwards.

Extracted out of https://github.com/go-gitea/gitea/pull/39865.

*Written by Claude.*

Co-authored-by: silverwind <me@silverwind.io>

models/issues/comment.go

@@ -1174,6 +1174,11 @@ func UpdateComment(ctx context.Context, c *Comment, contentVersion int, doer *us
 		if affected == 0 {
 			return ErrCommentAlreadyChanged
 		}
+		if c.Type == CommentTypeReview {
+			if _, err := db.GetEngine(ctx).ID(c.ReviewID).Cols("content").NoAutoTime().Update(&Review{Content: c.Content}); err != nil { // updated_unix picks a reviewer's latest review
+				return err
+			}
+		}
 		if err := c.LoadIssue(ctx); err != nil {
 			return err
 		}

tests/integration/api_pull_review_test.go

@@ -130,6 +130,12 @@ func testAPIPullReviewGeneral(t *testing.T) {
 	assert.EqualValues(t, "APPROVED", review.State)
 	assert.Equal(t, 3, review.CodeCommentsCount)
 
+	reviewComment := unittest.AssertExistsAndLoadBean(t, &issues_model.Comment{ReviewID: review.ID, Type: issues_model.CommentTypeReview})
+	req = NewRequestWithJSON(t, http.MethodPatch, fmt.Sprintf("/api/v1/repos/%s/%s/issues/comments/%d", repo.OwnerName, repo.Name, reviewComment.ID), &api.EditIssueCommentOption{Body: "just one nit"}).AddTokenAuth(getTokenForLoggedInUser(t, session, auth_model.AccessTokenScopeWriteIssue))
+	MakeRequest(t, req, http.StatusOK)
+	req = NewRequest(t, http.MethodGet, fmt.Sprintf("/api/v1/repos/%s/%s/pulls/%d/reviews/%d", repo.OwnerName, repo.Name, pullIssue.Index, review.ID)).AddTokenAuth(token)
+	assert.Equal(t, "just one nit", DecodeJSON(t, MakeRequest(t, req, http.StatusOK), &api.PullReview{}).Body)
+
 	// test dismiss review
 	req = NewRequestWithJSON(t, http.MethodPost, fmt.Sprintf("/api/v1/repos/%s/%s/pulls/%d/reviews/%d/dismissals", repo.OwnerName, repo.Name, pullIssue.Index, review.ID), &api.DismissPullReviewOptions{
 		Message: "test",