From 4408a9e0059df53cc9fd248c268e79ab4e4d1c69 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Motiejus=20Jak=C5=A1tys?= <motiejus@jakstys.lt>
Date: Thu, 9 Jun 2022 14:22:19 +0300
Subject: [PATCH] rootfs: remove ./ prefix from filenames

I've seen a container (private one) whose filenames start with ./, but
the layer name does not have the prefix, causing undocker to fail.

Let's always normalize the names to not have the prefix.
---
 rootfs/rootfs.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/rootfs/rootfs.go b/rootfs/rootfs.go
index 8494b36..5de314b 100644
--- a/rootfs/rootfs.go
+++ b/rootfs/rootfs.go
@@ -69,7 +69,7 @@ func Flatten(rd io.ReadSeeker, w io.Writer) (_err error) {
 			if err != nil {
 				return err
 			}
-			layerOffsets[hdr.Name] = here
+			layerOffsets[strings.TrimPrefix(hdr.Name, "./")] = here
 		}
 	}
 
@@ -82,7 +82,7 @@ func Flatten(rd io.ReadSeeker, w io.Writer) (_err error) {
 	for i, name := range manifest[0].Layers {
 		layers[i] = nameOffset{
 			name:   name,
-			offset: layerOffsets[name],
+			offset: layerOffsets[strings.TrimPrefix(name, "./")],
 		}
 	}