[PATCH] docs: mention cygwin shortcoming in <sys/un.h>

[Eric Blake]

I'm not quite ready to implement a replacement <sys/un.h> that
automatically works around this problem, since making the replacement
work for mingw seems much harder; so for now I'm just documenting
the issue I hit.

* doc/posix-headers/sys_un.texi (sys/un.h): Mention problem.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog                     | 5 +++++
 doc/posix-headers/sys_un.texi | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 617901a..a20c1fb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-05-30  Eric Blake  <address@hidden>
+
+       docs: mention cygwin shortcoming in <sys/un.h>
+       * doc/posix-headers/sys_un.texi (sys/un.h): Mention problem.
+
 2013-05-29  Eric Blake  <address@hidden>

        vasnprintf: silence mingw compiler warning
diff --git a/doc/posix-headers/sys_un.texi b/doc/posix-headers/sys_un.texi
index 78c848e..2297a13 100644
--- a/doc/posix-headers/sys_un.texi
+++ b/doc/posix-headers/sys_un.texi
@@ -14,4 +14,8 @@ sys/un.h
 @item
 This header file is missing on some platforms:
 mingw, MSVC 9, BeOS.
address@hidden
+This header requires <code>sys/socket.h</code> to be included first on
+some platforms:
+Cygwin 1.7.18.
 @end itemize
-- 
1.8.1.4