Windows installer (6.12.3) issues

Collecting some current issues to avoid in forthcoming installers (there does not seem to be an installer category?). I don't know when these were introduced, but I've just reinstalled ghc-6.12.3 to make sure these are due to the installer.

1. .hs is still registered to ghc_haskell (cf. #916 (closed)). I lost my existing shell command additions for that file type, but did not check whether that happened during uninstall or install.
2. The icons directory doesn't exist, no ghc/haskell icon for .hs files

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\ghc_haskell\DefaultIcon
    (Standard)    REG_SZ    C:\haskell\ghc\ghc-6.12.3\icons\hsicon.ico

1. I've uninstalled, then installed GHC, but ghc-pkg list still reports remnants of previous install (after ghc-pkg recache, it still lists ghc-paths, from the local package db). Is that intended? Is it documented which parts of an installation should survive (ghci.conf: yes; filetype associations and commands should, but don't; anything else?)?
2. ghc-pkg field * haddock-html lists the lib/* directories, not anything related to documentation (with the original installer, you need to issue this command in an empty directory, to work around #4156 (closed)).

$ ghc-pkg field * haddock-html
haddock-html: C:\haskell\datadir\doc\ghc-paths-0.1.0.6\html
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/Win32-2.2.0.2
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/time-1.1.4
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/template-haskell-2.4.0.1
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/syb-0.1.0.2
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/random-1.0.0.2
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/process-1.0.1.3
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/pretty-1.0.1.1
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/old-time-1.0.0.5
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/old-locale-1.0.0.2
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/integer-gmp-0.2.0.1
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/hpc-0.5.0.5
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/haskell98-1.0.1.1
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/ghc-prim-0.2.0.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/ghc-binary-0.5.0.2
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/ghc-6.12.3
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/filepath-1.1.0.4
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/extensible-exceptions-0.1.1.1
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/dph-seq-0.4.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/dph-prim-seq-0.4.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/dph-prim-par-0.4.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/dph-prim-interface-0.4.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/dph-par-0.4.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/dph-base-0.4.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/directory-1.0.1.1
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/containers-0.3.0.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/Cabal-1.8.0.6
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/bytestring-0.9.1.7
haddock-html:
haddock-html:
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/bin-package-db-0.0.0.0
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/base-4.2.0.2
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/base-3.0.3.2
haddock-html: C:/haskell/ghc/ghc-6.12.3\lib/array-0.3.0.1

1. Documentation cross-links are thoroughly messed up (the urls seem to be missing the package identifier): eg, the Bool in Data.List refer to libraries/Data-Bool.. instead of libraries/base-4.2.0.2%5CData-Bool..
2. Trying to cabal-install packages on top of this leads to documentation problems:

Running Haddock for ghc-paths-0.1.0.6...
Preprocessing library ghc-paths-0.1.0.6...
Warning: The documentation for the following packages are not installed. No
links will be generated to these packages: base-4.2.0.2, ffi-1.0, rts-1.0,
ghc-prim-0.2.0.0, integer-gmp-0.2.0.1
Warning: GHC.Paths: could not find link destinations for:
    GHC.IO.FilePath

Trac metadata

Trac field	Value
Version	6.12.3
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	None
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