From 87b9b385b38795c58bc13ffb33b8724bed27f7a0 Mon Sep 17 00:00:00 2001
From: Johannes Schauer Marin Rodrigues <josch@mister-muffin.de>
Date: Fri, 13 Sep 2024 01:16:31 +0200
Subject: [PATCH] tarfilter: do not rely on paths being absolute (starting with
 a single slash)

---
 tarfilter | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/tarfilter b/tarfilter
index 66ef229..ad77616 100755
--- a/tarfilter
+++ b/tarfilter
@@ -218,8 +218,11 @@ Lastly, shift user id and group id of each entry by the value given by the
         skip = False
         if not hasattr(args, "pathfilter"):
             return False
+        # normalize path and make it absolute by stripping off all leading
+        # dots and slashes and then prepending a slash
+        name = "/" + member.name.lstrip("./")
         for t, r in args.pathfilter:
-            if r.match(member.name[1:]) is not None:
+            if r.match(name) is not None:
                 if t == "path_include":
                     skip = False
                 else:
@@ -230,7 +233,7 @@ Lastly, shift user id and group id of each entry by the value given by the
                     continue
                 prefix = prefix_prog.sub(r"\1", r.pattern)
                 prefix = prefix.rstrip("/")
-                if member.name[1:].startswith(prefix):
+                if name.startswith(prefix):
                     return False
         return skip