--- a/mercurial/revlogutils/deltas.py Mon May 03 20:22:34 2021 +0200
+++ b/mercurial/revlogutils/deltas.py Mon May 03 19:46:25 2021 +0200
@@ -553,6 +553,24 @@
snapshotdepth = attr.ib()
+def drop_u_compression(delta):
+ """turn into a "u" (no-compression) into no-compression without header
+
+ This is useful for revlog format that has better compression method.
+ """
+ assert delta.data[0] == b'u', delta.data[0]
+ return _deltainfo(
+ delta.distance,
+ delta.deltalen - 1,
+ (b'', delta.data[1]),
+ delta.base,
+ delta.chainbase,
+ delta.chainlen,
+ delta.compresseddeltalen,
+ delta.snapshotdepth,
+ )
+
+
def isgooddeltainfo(revlog, deltainfo, revinfo):
"""Returns True if the given delta is good. Good means that it is within
the disk span, disk size, and chain length bounds that we know to be