avoid crashing when there are remotes using unparseable urls

Including the non-standard URI form that git-remote-gcrypt uses for rsync.

Eg, "ook://foo:bar" cannot be parsed because "bar" is not a valid port
number. But git could have a remote with that, it would try to run
git-remote-ook to handle it. So, git-annex has to allow for such things,
rather than crashing.

This commit was sponsored by Luke Shumaker on Patreon.

Git/Url.hs

@@ -1,6 +1,6 @@
 {- git repository urls
  -
- - Copyright 2010, 2011 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -23,6 +23,7 @@ import Git
 {- Scheme of an URL repo. -}
 scheme :: Repo -> String
 scheme Repo { location = Url u } = uriScheme u
+scheme Repo { location = UnparseableUrl u } = unparseableUrl u
 scheme repo = notUrl repo
 
 {- Work around a bug in the real uriRegName
@@ -65,13 +66,18 @@ authority = authpart assemble
 {- Applies a function to extract part of the uriAuthority of an URL repo. -}
 authpart :: (URIAuth -> a) -> Repo -> Maybe a
 authpart a Repo { location = Url u } = a <$> uriAuthority u
+authpart _ Repo { location = UnparseableUrl u } = unparseableUrl u
 authpart _ repo = notUrl repo
 
 {- Path part of an URL repo. -}
 path :: Repo -> FilePath
 path Repo { location = Url u } = uriPath u
+path Repo { location = UnparseableUrl u } = unparseableUrl u
 path repo = notUrl repo
 
 notUrl :: Repo -> a
 notUrl repo = error $
 	"acting on local git repo " ++ repoDescribe repo ++ " not supported"
+
+unparseableUrl :: String -> a
+unparseableUrl u = error $ "unable to parse repo url " ++ u