Preconditions:

• Set up a multibranch pipeline with 5 branches and 10 runs for each branch.

Repro Steps
1. Navigate to the Activity branch for the MBP
2. Note there are 25 runs displayed
3. Press "Show More"

Expected Result

• A total of 50 runs should be displayed

Actual Results

• No addition runs are displayed and the "Show More" button disappears

Analysis:
When the second request is made, it hits the /activities endpoint sending parameters of start=25 and limit=26. This request returns an empty array.

The bug appears to be in MultiBranchPipelineImpl.getRuns() which is called from getActivities(). Inside of the anonymous BlueRunContainer.iterator(int start, int limit) method there is a bug around line 281:

for(final BluePipeline b: branches) {
    Iterator<BlueRun> it = b.getRuns().iterator(0,MAX_MBP_RUNS_ROWS);
    int count = 0;
    Iterators.skip(it, start);
    while(it.hasNext() && count++ < limit){
        c.add(it.next());
    }
}

The problem is that the runs iterator for each branch skips forward based on the value of start (25). Since each branch only has 10 runs, each branch returns zero results, yielding an empty collection.