commit efc81216a1bffe599477cca32cf9d82307109ca9
author Wyatt Allen <wyatta@google.com> Mon Aug 20 16:40:48 2018 -0700
committer Wyatt Allen <wyatta@google.com> Fri Sep 14 13:43:19 2018 -0700
tree 302511ef9bc66554ebf2cd2c67f5e8d0c417cacc
parent 47032f3648a6290ccc6e5fc5750e226d953a7d80

Add ignore-whitespace control

When a diff request includes an ignore-whitespace level, the same diff
content is returned, but a number of diff chunks are marked as "common"
with the understanding that those chunks only contain the kind of
whitespace that can be ignored. Thus, actually ignoring these chunks is
up to the frontend.

In this commit, support is added for editing the preferred whitespace
level, and the preferred level is included in diff requests. When a diff
is loaded with an ignore-whitespace level, gr-diff-host transforms the
marked deltas into shared chunks. In this way, when the transformed diff
is passed down into gr-diff, it can be rendered like normal and the
unwanted whitespace deltas do not appear.

To transform a diff with chunks to be ignored, the strategy is as
follows. If a marked delta chunk has revision (a right-side), then it's
converted to a shared chunk where both sides are made up of the revision
content. (If a marked delta chunk has no revision content, it's merely
omitted.) Finally, adjacent shared chunks that result from modifying
the marked chunks are merged together so that gr-diff will properly
position context-control barriers.

Feature: Issue 6198
Change-Id: I1e4cc1075edf34f5ce87ee6bfc2cf415a3b98d94