encoding error on long UTF-8 paste

[judah]

Pasting the following input (in a UTF-8 environment), including the trailing newline:

line 4:1:ασδφαδφασφασδφσδφασφξασηδφασδκξφηασδκηφκξσδηφασδξφγδσγφηδσγφξκγδσξηφγαξδφηγακφξηγσφκξαησγδφξκηασδγφκξασδηγφκξαησδγφξασηδφγακσξδηφγασδκξηφγακδσξηφγαξκδσφγδσξηφγαδκσφηγκσξδηφγαξφησγδκφξαησγφκξαδσηφγξσδφηγαδσξφγαησδγφκξαησφγκαξσηδφγακσδξφηγασκξφηαγδφξκαηγσδκφξηαγξδφξα1:ασδφαδφασφασδφσδφασφξασηδφασδκξφηασδκηφκξσδηφασδξφγδσγφηδσγφξκγδσξηφγαξδφηγακφξηγσφκξαησγδφξκηασδγφκξασδηγφκξαησδγφξασηδφγακσξδηφγασδκξηφγακδσξηφγαξκδσφγδσξηφγαδκσφηγκσξδηφγαξφησγδκφξαησγφκξαδσηφγξσδφηγαδσξφγαησδγφκξαησφγκαξσηδφγακσδξφηγασκξφηαγδφξκαηγσδκφξηαγξδφξα

causes the following error:

<stdin>: hWaitForInput: invalid argument (Illegal byte sequence)

Additionally, the last character before the error is output as a '?'.

[judah]

See also #94.

It looks like we'll need to keep our own buffer, and also use hGetBufSome instead of hWaitForInput with ghc>=6.13. See http://hackage.haskell.org/trac/ghc/ticket/4046 .