[newlib-cygwin] Cygwin: check for STATUS_PENDING in fhandler_base::raw_read

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=10bf30bebf7feebbc3e376cbcac62a242cc240f3

commit 10bf30bebf7feebbc3e376cbcac62a242cc240f3
Author: Ken Brown <kbrown@cornell.edu>
Date:   Sun Apr 14 19:15:59 2019 +0000

    Cygwin: check for STATUS_PENDING in fhandler_base::raw_read
    
    If NtReadFile returns STATUS_PENDING, wait for the read to complete.
    This can happen, for instance, in the case of a FIFO opened with
    O_RDRW.

Diff:
---
 winsup/cygwin/fhandler.cc | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/winsup/cygwin/fhandler.cc b/winsup/cygwin/fhandler.cc
index b0c9c50..a0c3dcc 100644
--- a/winsup/cygwin/fhandler.cc
+++ b/winsup/cygwin/fhandler.cc
@@ -215,11 +215,23 @@ fhandler_base::raw_read (void *ptr, size_t& len)
   NTSTATUS status;
   IO_STATUS_BLOCK io;
   int try_noreserve = 1;
+  DWORD waitret = WAIT_OBJECT_0;
 
 retry:
   status = NtReadFile (get_handle (), NULL, NULL, NULL, &io, ptr, len,
 		       NULL, NULL);
-  if (NT_SUCCESS (status))
+  if (status == STATUS_PENDING)
+    {
+      waitret = cygwait (get_handle (), cw_infinite,
+			 cw_cancel | cw_sig_eintr);
+      if (waitret == WAIT_OBJECT_0)
+	status = io.Status;
+    }
+  if (waitret == WAIT_CANCELED)
+    pthread::static_cancel_self ();
+  else if (waitret == WAIT_SIGNALED)
+    set_errno (EINTR);
+  else if (NT_SUCCESS (status))
     len = io.Information;
   else
     {