Add undopatch script

1 files changed, 11 insertions, 5 deletions

diff --git a/README b/README
index ca429cb..13f65cb 100644
--- a/README
+++ b/README
@@ -30,15 +30,21 @@ they are formatted correctly and placed in the correct directory.
 
 = Undoing patches =
 
-I haven't tried it yet, but the following command should work:
+In order to undo all patches, you need to extract the original
+files from the downloaded archive.
 
-	cd /usr/pkgsrc/path-to/package/work/
+	cd /usr/pkgsrc/path-to/package
+	w=/usr/pkgsrc/distfiles/$(sed -n '/.*(\(.*\)).*/{s//\1/;p;q}' distinfo)
+	cd $(dirname $w)
+	tar xf $w
+	cd -
 	find . -name '*.orig' | while read f; do
-		mv "$f" "${f%.orig}"
+		f=${f%.orig}
+		cp $w/${f#work/} $f
 	done
 
-It probably won't work if you've tried to apply patches twice, as
-each do-patch theoretically presumably creates new .orig files.
+It is not reliable to restore the original files using the .orig
+files, as multiple patches may have been applied to the same file.
 
 = Rebuilding with new patch =