--- a/mercurial/dagop.py Fri Mar 09 21:59:07 2018 -0500
+++ b/mercurial/dagop.py Wed Feb 28 15:09:05 2018 -0500
@@ -9,6 +9,9 @@
import heapq
+from .thirdparty import (
+ attr,
+)
from . import (
error,
mdiff,
@@ -358,6 +361,74 @@
if inrange:
yield c, linerange1
+@attr.s(slots=True, frozen=True)
+class annotateline(object):
+ fctx = attr.ib()
+ lineno = attr.ib(default=False)
+ # Whether this annotation was the result of a skip-annotate.
+ skip = attr.ib(default=False)
+
+def _annotatepair(parents, childfctx, child, skipchild, diffopts):
+ r'''
+ Given parent and child fctxes and annotate data for parents, for all lines
+ in either parent that match the child, annotate the child with the parent's
+ data.
+
+ Additionally, if `skipchild` is True, replace all other lines with parent
+ annotate data as well such that child is never blamed for any lines.
+
+ See test-annotate.py for unit tests.
+ '''
+ pblocks = [(parent, mdiff.allblocks(parent[1], child[1], opts=diffopts))
+ for parent in parents]
+
+ if skipchild:
+ # Need to iterate over the blocks twice -- make it a list
+ pblocks = [(p, list(blocks)) for (p, blocks) in pblocks]
+ # Mercurial currently prefers p2 over p1 for annotate.
+ # TODO: change this?
+ for parent, blocks in pblocks:
+ for (a1, a2, b1, b2), t in blocks:
+ # Changed blocks ('!') or blocks made only of blank lines ('~')
+ # belong to the child.
+ if t == '=':
+ child[0][b1:b2] = parent[0][a1:a2]
+
+ if skipchild:
+ # Now try and match up anything that couldn't be matched,
+ # Reversing pblocks maintains bias towards p2, matching above
+ # behavior.
+ pblocks.reverse()
+
+ # The heuristics are:
+ # * Work on blocks of changed lines (effectively diff hunks with -U0).
+ # This could potentially be smarter but works well enough.
+ # * For a non-matching section, do a best-effort fit. Match lines in
+ # diff hunks 1:1, dropping lines as necessary.
+ # * Repeat the last line as a last resort.
+
+ # First, replace as much as possible without repeating the last line.
+ remaining = [(parent, []) for parent, _blocks in pblocks]
+ for idx, (parent, blocks) in enumerate(pblocks):
+ for (a1, a2, b1, b2), _t in blocks:
+ if a2 - a1 >= b2 - b1:
+ for bk in xrange(b1, b2):
+ if child[0][bk].fctx == childfctx:
+ ak = min(a1 + (bk - b1), a2 - 1)
+ child[0][bk] = attr.evolve(parent[0][ak], skip=True)
+ else:
+ remaining[idx][1].append((a1, a2, b1, b2))
+
+ # Then, look at anything left, which might involve repeating the last
+ # line.
+ for parent, blocks in remaining:
+ for a1, a2, b1, b2 in blocks:
+ for bk in xrange(b1, b2):
+ if child[0][bk].fctx == childfctx:
+ ak = min(a1 + (bk - b1), a2 - 1)
+ child[0][bk] = attr.evolve(parent[0][ak], skip=True)
+ return child
+
def toposort(revs, parentsfunc, firstbranch=()):
"""Yield revisions from heads to roots one (topo) branch at a time.