--- a/mercurial/context.py	Sun Oct 16 18:03:24 2016 +0900
+++ b/mercurial/context.py	Sun Feb 19 19:37:14 2017 +0900
@@ -1272,89 +1272,6 @@
         return [filectx(self._repo, self._path, fileid=x,
                         filelog=self._filelog) for x in c]
 
-def _changesrange(fctx1, fctx2, linerange2, diffopts):
-    """Return `(diffinrange, linerange1)` where `diffinrange` is True
-    if diff from fctx2 to fctx1 has changes in linerange2 and
-    `linerange1` is the new line range for fctx1.
-    """
-    blocks = mdiff.allblocks(fctx1.data(), fctx2.data(), diffopts)
-    filteredblocks, linerange1 = mdiff.blocksinrange(blocks, linerange2)
-    diffinrange = any(stype == '!' for _, stype in filteredblocks)
-    return diffinrange, linerange1
-
-def blockancestors(fctx, fromline, toline, followfirst=False):
-    """Yield ancestors of `fctx` with respect to the block of lines within
-    `fromline`-`toline` range.
-    """
-    diffopts = patch.diffopts(fctx._repo.ui)
-    introrev = fctx.introrev()
-    if fctx.rev() != introrev:
-        fctx = fctx.filectx(fctx.filenode(), changeid=introrev)
-    visit = {(fctx.linkrev(), fctx.filenode()): (fctx, (fromline, toline))}
-    while visit:
-        c, linerange2 = visit.pop(max(visit))
-        pl = c.parents()
-        if followfirst:
-            pl = pl[:1]
-        if not pl:
-            # The block originates from the initial revision.
-            yield c, linerange2
-            continue
-        inrange = False
-        for p in pl:
-            inrangep, linerange1 = _changesrange(p, c, linerange2, diffopts)
-            inrange = inrange or inrangep
-            if linerange1[0] == linerange1[1]:
-                # Parent's linerange is empty, meaning that the block got
-                # introduced in this revision; no need to go futher in this
-                # branch.
-                continue
-            # Set _descendantrev with 'c' (a known descendant) so that, when
-            # _adjustlinkrev is called for 'p', it receives this descendant
-            # (as srcrev) instead possibly topmost introrev.
-            p._descendantrev = c.rev()
-            visit[p.linkrev(), p.filenode()] = p, linerange1
-        if inrange:
-            yield c, linerange2
-
-def blockdescendants(fctx, fromline, toline):
-    """Yield descendants of `fctx` with respect to the block of lines within
-    `fromline`-`toline` range.
-    """
-    # First possibly yield 'fctx' if it has changes in range with respect to
-    # its parents.
-    try:
-        c, linerange1 = next(blockancestors(fctx, fromline, toline))
-    except StopIteration:
-        pass
-    else:
-        if c == fctx:
-            yield c, linerange1
-
-    diffopts = patch.diffopts(fctx._repo.ui)
-    fl = fctx.filelog()
-    seen = {fctx.filerev(): (fctx, (fromline, toline))}
-    for i in fl.descendants([fctx.filerev()]):
-        c = fctx.filectx(i)
-        inrange = False
-        for x in fl.parentrevs(i):
-            try:
-                p, linerange2 = seen[x]
-            except KeyError:
-                # nullrev or other branch
-                continue
-            inrangep, linerange1 = _changesrange(c, p, linerange2, diffopts)
-            inrange = inrange or inrangep
-            # If revision 'i' has been seen (it's a merge), we assume that its
-            # line range is the same independently of which parents was used
-            # to compute it.
-            assert i not in seen or seen[i][1] == linerange1, (
-                'computed line range for %s is not consistent between '
-                'ancestor branches' % c)
-            seen[i] = c, linerange1
-        if inrange:
-            yield c, linerange1
-
 class committablectx(basectx):
     """A committablectx object provides common functionality for a context that
     wants the ability to commit, e.g. workingctx or memctx."""