[commit: ghc] master: base: Mention openFile throwing does-not-exist-errors on FIFOs (4ba3fa3)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/4ba3fa31ddfa12b428bd67216a2d4118dc9e8311/ghc

>---------------------------------------------------------------

commit 4ba3fa31ddfa12b428bd67216a2d4118dc9e8311
Author: Ben Gamari <bgamari.foss at gmail.com>
Date:   Thu Nov 22 11:33:39 2018 -0500

    base: Mention openFile throwing does-not-exist-errors on FIFOs
    
    As discussed in #15715, the POSIX specification specifies that
    attempting to open a FIFO in write-only mode when the FIFO has no
    readers will fail with -ENOENT.
    
    [skip ci]
    
    Test Plan: Read it
    
    Reviewers: hvr
    
    Subscribers: rwbarton, carter
    
    GHC Trac Issues: #15715
    
    Differential Revision: https://phabricator.haskell.org/D5295


>---------------------------------------------------------------

4ba3fa31ddfa12b428bd67216a2d4118dc9e8311
 libraries/base/GHC/IO/Handle/FD.hs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libraries/base/GHC/IO/Handle/FD.hs b/libraries/base/GHC/IO/Handle/FD.hs
index 883bc5f..6417976 100644
--- a/libraries/base/GHC/IO/Handle/FD.hs
+++ b/libraries/base/GHC/IO/Handle/FD.hs
@@ -131,7 +131,9 @@ addFilePathToIOError fun fp ioe
 --  * 'System.IO.Error.isAlreadyInUseError' if the file is already open and
 --    cannot be reopened;
 --
---  * 'System.IO.Error.isDoesNotExistError' if the file does not exist; or
+--  * 'System.IO.Error.isDoesNotExistError' if the file does not exist or
+--    (on POSIX systems) is a FIFO without a reader and 'WriteMode' was
+--    requested; or
 --
 --  * 'System.IO.Error.isPermissionError' if the user does not have permission
 --     to open the file.