Comment 46 for bug 1770044

Thanks so much for looking into this! Unfortunately, the crash is still there.

(Sorry for the late reply, but for some reason I wasn’t notified that this report had been updated.)

However, your changes made it a bit easier for me to continue debugging this. As it turns out, the problem appears to be that I have two jobs that have the same id. That is, within getJobFinished(), the 'jobs' variable (KCupsJobs) contains four jobs, and the first two have the same .id(). (They also have the same .name().) I have four jobs in total.

Here is what happens inside the for loop over the KCupsJobs (the JobModel is initially empty, i.e. rowCount() == 0 at the start)

- Iteration/job 0: jobRow() for this KCupsJob returns -1, which means that the job isn’t in the model. The job is inserted at index 0.

- Iteration/job 1: jobRow() for this KCupsJob returns 0 because this KCupsJob has the same id as the one that was just inserted. updateJob() is called for row 0. Then the condition in "if (job_row != i)" is true ("found at wrong position") and the code tries to take row 0 and insert it at index 2. This fails for some reason so that there are actually no rows in the model anymore (rowCount() == 0). Perhaps insertRow() has undefined behavior when the given row index is greater than rowCount()?

- Iteration/job 2: jobRow() for this KCupsJob returns -1 as it is a different job. The code tries to insert it at index 2. insertJob() calls updateJob() with pos = 2, which crashes at some point because rowCount() is actually 0.

I have no idea why the duplicate jobs exist, but they are also visible on <http://localhost:631/jobs/>, so they’re real.

I’ve attempted to fix the problem in getJobFinished() by just inserting all jobs when the model is empty:

if (rowCount() == 0) {
    for (int i = 0; i < jobs.size(); ++i) {
        insertJob(i, jobs.at(i));
    }
} else {
    // (previous loop here)

For me, this avoids the crash during startup. (I’m not suggesting this is a proper fix.)