hgweb: use patch.diffhunks in webutil.diffs to simplify the algorithm
Function patch.diffhunks yields items for a "block" (i.e. a file) as a whole
so take advantage of this to simplify the algorithm and avoid parsing diff
lines to determine whether we're starting a new "block" or not. Thus we drop
to external block counter and rely on diffhunks iterations instead.
We also take advantage of the fact that patch.diffhunks() yields *lines* of
hunks (instead of a string) to avoid building a list that is ''.join-ed into a
string that is then split.
As lines in 'header' returned by patch.diffhunks() have no trailing new line,
we need to insert it ourselves to match template expectations.
$ hg init repo
$ cd repo
$ touch foo
$ hg ci -Am 'add foo'
adding foo
$ hg up -C null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
this should be stored as a delta against rev 0
$ echo foo bar baz > foo
$ hg ci -Am 'add foo again'
adding foo
created new head
$ hg debugindex foo
rev offset length ..... linkrev nodeid p1 p2 (re)
0 0 0 ..... 0 b80de5d13875 000000000000 000000000000 (re)
1 0 13 ..... 1 0376abec49b8 000000000000 000000000000 (re)
$ cd ..