Update tests and docs for obsolete fields in tarball importssam/tarball-obsolete-fields

The 'compression' and 'strip' fields seem to have been obsolete since
commit a7f8b1b63a97c66aea6f39342313d7a5b919cfa7 in 2012.

1 files changed, 12 insertions, 8 deletions

diff --git a/README b/README
index 07b43bf..a171a66 100644
--- a/README
+++ b/README
@@ -177,18 +177,22 @@ as the project name.
 	}
 
 ### Tarball
-Some projects are old enough to pre-date version control, so the source is only
-available in tarballs.
-Tarball support is fairly limited, the compression format is currently specified
-as the long form option without the --, so --gzip becomes gzip.
-Strip removes that many components from the paths. This is necessary as tarballs
-often have the folder name as the first component.
+
+Lorry can import a tarball fetched from a URL. The contents will be
+committed on a branch named after the basename of the tar file (e.g.
+bc-1.06.tar.gz will be imported into a branch named 'bc-1.06'.
+
+The import is done by the `lorry.tar-importer` subprocess. It can detect and
+handle common compression formats including gzip, bz2, xz and lzma. It will
+also detect if there is a 'top directory' that contains the tarball contents
+and strip this out of the imported filenames.
+
+Tarball imports once required 'compression' and 'strip' to be specified.
+These are obsolete now and are ignored by Lorry.
 
 {
     "bc": {
         "type": "tarball",
-        "compression": "gzip",
-        "strip": 1,
         "url": "http://ftp.gnu.org/gnu/bc/bc-1.06.tar.gz"
     }
 }