cleanup based on comments about outstanding work

Author: gbaz

src/Distribution/Server/Features/PackageCandidates.hs

@@ -222,6 +222,11 @@ candidatesFeature ServerEnv{serverBlobStore = store}
             resourceDesc = [(GET, "Candidate tarball")]
           , resourceGet  = [("tarball", serveCandidateTarball)]
           }
+      -- dummy null resource for revisions, since candidates don't have revisions
+      , coreCabalFileRev = (resourceAt "/package/:package/candidate/revisions/") {
+          resourceDesc = []
+        , resourceGet  = []
+      }
       , indexPackageUri = \format ->
           renderResource (corePackagesPage r) [format]
       , corePackageIdUri = \format pkgid ->

src/Distribution/Server/Packages/Unpack.hs

@@ -18,7 +18,7 @@ import qualified Codec.Archive.Tar.Entry as Tar
 import qualified Codec.Archive.Tar.Check as Tar
 
 import Distribution.CabalSpecVersion
-         ( CabalSpecVersion(..), showCabalSpecVersion )
+         ( CabalSpecVersion(..) )
 import Distribution.Version
          ( nullVersion )
 import Distribution.Types.PackageName
@@ -209,24 +209,8 @@ specVersionChecks specVerOk specVer = do
     throwError "'cabal-version' must be at least 1.2"
 
   -- Safeguard; should already be caught by parser
-  unless (specVer <= CabalSpecV2_4) $
-    throwError "'cabal-version' must be at most 2.4"
-
-  -- Check whether a known spec version had been used
-  -- TODO: move this into lib:Cabal
-  let knownSpecVersions =
-        [ CabalSpecV1_18
-        , CabalSpecV1_20
-        , CabalSpecV1_22
-        , CabalSpecV1_24
-        , CabalSpecV2_0
-        , CabalSpecV2_2
-        , CabalSpecV2_4
-        ]
-  when (specVer >= CabalSpecV1_18 && (specVer `notElem` knownSpecVersions)) $
-    throwError ("'cabal-version' refers to an unreleased/unknown cabal specification version "
-                ++ showCabalSpecVersion specVer ++ "; for a list of valid specification versions please consult "
-                ++ "https://www.haskell.org/cabal/users-guide/file-format-changelog.html")
+  unless (specVer <= CabalSpecV3_0) $
+    throwError "'cabal-version' must be at most 3.0"
 
 -- | The issue is that browsers can upload the file name using either unix
 -- or windows convention, so we need to take the basename using either