“Introducing new bugs” is as decisive as “compilation errors” and “test failures” to reject a patch: as shown in Figure 5, a patch is highly likely to be rejected if it causes compilation errors or fails tests. While this is to some extent expectable, it is interesting to see that reviewers have almost the same low tolerance for patches that introduce new bugs. In such cases, a patch that intends to fix a bug instead worsens the situation by introducing new problems.