# HG changeset patch
# User Mike Edgar <adgar@google.com>
# Date 1421876109 18000
# Node ID a5a06c9c74070ba84ddec1f1f5e9d3e7bbd28e19
# Parent  76f6ae06ddf578cbcafd94faaf69a31433a7282a
mdiff: add helper for making deltas which replace the full text of a revision

This helper will be used initially for censor-aware delta generation. Deltas
which replace the full contents of the base revision are guaranteed to apply
correctly regardless of whether the delta recipient has censored the base.

For background and broader design of the censorship feature, see:
http://mercurial.selenic.com/wiki/CensorPlan

diff -r 76f6ae06ddf5 -r a5a06c9c7407 mercurial/mdiff.py
--- a/mercurial/mdiff.py	Fri Jan 23 17:01:39 2015 -0500
+++ b/mercurial/mdiff.py	Wed Jan 21 16:35:09 2015 -0500
@@ -367,6 +367,9 @@
 def trivialdiffheader(length):
     return struct.pack(">lll", 0, 0, length)
 
+def replacediffheader(oldlen, newlen):
+    return struct.pack(">lll", 0, oldlen, newlen)
+
 patches = mpatch.patches
 patchedsize = mpatch.patchedsize
 textdiff = bdiff.bdiff