B. Developer Survey
Based on our manual inspection results, we conducted an online survey with Eclipse and Mozilla developers. In this survey, we asked developers to rate how decisive these 12 reasons for patch rejection are on a 5-point Likert scale (RQ2). To complement our manual inspection, we also asked developers to supplement additional patch-rejection reasons that they considered important but were not listed in our survey. Furthermore, as an attempt to quantify the cost of patch review, we asked developers to rate the difficulty of judging each reason for patch rejection on a 5-point Likert scale (Section IV-B).