X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fmain%2FPackages.lhs;fp=compiler%2Fmain%2FPackages.lhs;h=4c22b34108c96c7ff98bd056feb2307968fd4539;hp=4b1446280f8187560acc61eb3d7dc5b5ba629532;hb=45a8d0ceac35f657e8f367a0e0870f2df0acde93;hpb=41a801223a8bd07659ea1178df67912f5dc3d588

diff --git a/compiler/main/Packages.lhs b/compiler/main/Packages.lhs
index 4b14462..4c22b34 100644
--- a/compiler/main/Packages.lhs
+++ b/compiler/main/Packages.lhs
@@ -556,12 +556,13 @@ shadowPackages pkgs preferred
    in  listToFM shadowed
  where
  check (shadowed,pkgmap) pkg
-      | Just oldpkg <- lookupUFM pkgmap (packageConfigId pkg)
-      = let
-          ipid_new = installedPackageId pkg
-          ipid_old = installedPackageId oldpkg
-        in
-        if ipid_old `elem` preferred
+      | Just oldpkg <- lookupUFM pkgmap (packageConfigId pkg),
+        let
+            ipid_new = installedPackageId pkg
+            ipid_old = installedPackageId oldpkg,
+        --
+        ipid_old /= ipid_new
+      = if ipid_old `elem` preferred
            then ( (ipid_new, ShadowedBy ipid_old) : shadowed, pkgmap )
            else ( (ipid_old, ShadowedBy ipid_new) : shadowed, pkgmap' )
       | otherwise