[PATCH 5 of 7 V5] hgweb: add a 'linerange' parameter to webutil.diffs()

[Denis Laxalde]

# HG changeset patch
# User Denis Laxalde <denis.laxalde at logilab.fr>
# Date 1489414549 -3600
#      Mon Mar 13 15:15:49 2017 +0100
# Node ID 5b6a965fd0e2a1d0607672c5c6de70856e15df9f
# Parent  7f68dc6319094b00f78ede75a01af62801f6a765
# Available At https://hg.logilab.org/users/dlaxalde/hg
#              hg pull https://hg.logilab.org/users/dlaxalde/hg -r 5b6a965fd0e2
# EXP-Topic linerange-log/hgweb-filelog
hgweb: add a 'linerange' parameter to webutil.diffs()

This is used to filter out hunks based on their range (with respect to 'node2'
for patch.diffhunks() call, i.e. 'ctx' for webutil.diffs()).

This is the simplest way to filter diff hunks, here done on server side. Later
on, it might be interesting to perform this filtering on client side and
expose a "toggle" action to alternate between full and filtered diff.

diff --git a/mercurial/hgweb/webutil.py b/mercurial/hgweb/webutil.py
--- a/mercurial/hgweb/webutil.py
+++ b/mercurial/hgweb/webutil.py
@@ -434,7 +434,7 @@ def listfilediffs(tmpl, files, node, max
     if len(files) > max:
         yield tmpl('fileellipses')
 
-def diffs(web, tmpl, ctx, basectx, files, style):
+def diffs(web, tmpl, ctx, basectx, files, style, linerange=None):
 
     def prettyprintlines(lines, blockno):
         for lineno, l in enumerate(lines, 1):
@@ -470,6 +470,11 @@ def diffs(web, tmpl, ctx, basectx, files
             header = header[1:]
         lines = [h + '\n' for h in header]
         for hunkrange, hunklines in hunks:
+            if linerange is not None and hunkrange is not None:
+                s1, l1, s2, l2 = hunkrange
+                lb, ub = linerange
+                if not (lb <= s2 < ub or lb < s2 + l2 <= ub):
+                    continue
             lines.extend(hunklines)
         if lines:
             yield tmpl('diffblock', parity=next(parity), blockno=blockno,