PR#5416: better implementation of set/clear_close_on_exec

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@11888 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

2 files changed, 6 insertions, 8 deletions

diff --git a/Changes b/Changes
index 7b22c2fc3..c96bd2234 100644
--- a/Changes
+++ b/Changes
@@ -31,6 +31,7 @@ Standard library:
       with user-provided hash functions.
 
 Bug Fixes:
+- PR#5416: (Windows) Unix.(set|clear)_close_on_exec now preserves blocking mode
 - PR#5343: ocaml -rectypes is unsound wrt module subtyping
 - PR#5322: type abbreviations expanding to a universal type variable
 - PR#5330: thread tag with '.top' and '.inferred.mli' targets
diff --git a/otherlibs/win32unix/close_on.c b/otherlibs/win32unix/close_on.c
index b64dd44dd..03ff2b894 100644
--- a/otherlibs/win32unix/close_on.c
+++ b/otherlibs/win32unix/close_on.c
@@ -19,17 +19,14 @@
 
 int win_set_inherit(value fd, BOOL inherit)
 {
-  HANDLE oldh, newh;
-
-  oldh = Handle_val(fd);
-  if (! DuplicateHandle(GetCurrentProcess(), oldh,
-                        GetCurrentProcess(), &newh,
-                        0L, inherit, DUPLICATE_SAME_ACCESS)) {
+  /* According to the MSDN, SetHandleInformation may not work
+     for console handles on WinNT4 and earlier versions. */
+  if (! SetHandleInformation(Handle_val(fd),
+			     HANDLE_FLAG_INHERIT,
+			     inherit ? HANDLE_FLAG_INHERIT : 0)) {
     win32_maperr(GetLastError());
     return -1;
   }
-  Handle_val(fd) = newh;
-  CloseHandle(oldh);
   return 0;
 }