[GHC] #869: Foreign.C.String.withCStringLen doesn't terminate C string by NUL

[GHC]

#869: Foreign.C.String.withCStringLen doesn't terminate C string by NUL
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  Reporter:  guest           |          Owner:       
      Type:  bug             |         Status:  new  
  Priority:  normal          |      Milestone:       
 Component:  libraries/base  |        Version:  6.4.2
  Severity:  normal          |     Resolution:       
  Keywords:                  |             Os:  Linux
Difficulty:  Unknown         |   Architecture:  x86  
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Comment (by duncan):

 From my reading of the FFI spec CStringLen is not required to be nul
 terminated. So I think the code is correct and the documentation is wrong.

 {{{
 type CString = Ptr CChar
     A C string is a reference to an array of C characters
     terminated by NUL.

 type CStringLen = (Ptr CChar, Int)
     In addition to NUL-terminated strings, the module CString also
     supports strings with explicit length information in bytes.

 newCString :: String -> IO CString
 newCStringLen :: String -> IO CStringLen
   Allocate a memory area for a Haskell string and marshal the
   string into its C representation. There are two variants of
   the routine, one for each supported string representation.

 withCString :: String -> (CString -> IO a) -> IO a
 withCStringLen :: String -> (CStringLen -> IO a) -> IO a
   These two routines operate as newCString and newCStringLen,
   respectively, but handle memory allocation and deallocation
   like MarshalAlloc.alloca (Section 5.8).
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/869>
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