Show cumulative diffs in the diffviewer

Review Request #10123 — Created Aug. 21, 2018 and submitted — Latest diff uploaded

Information

Review Board
release-4.0.x
7e6d551...

Reviewers

Previously, FileDiffs for review requests with history would not show
cumulatively. That is, you would see only the result of applying that
FileDiff, not the result of applying the entire stack of FileDiffs
in the history graph.

We now compute the entire file history, including deletions, and use
that to compute the cumulative diff. In other words, for a review
request with commits A -> B -> C where all three commits modify the
same file, previously you would see the result of A, B, and C
independently. Now the diffviewer shows A, A..B, and A..C.

Files are still repeated (as indicated above) so this is not yet a true
cumulative diff. A future patch will update the diffviewer to only show
the leaf FileDiffs in the history graph.

  • Ran unit tests.
  • Uploaded a multi-commit review request and looked at the diff. I
    observed cumulative (but repeated) diffs.