# 
# 
# patch "ChangeLog"
#  from [98a19c78fc79c05644fcf3d868600397997533b3]
#    to [3bfb1366ba32a5dee36ab5542a74c36831cf18d0]
# 
# patch "configure.ac"
#  from [0bbe01c42c3d25e72176fda5c606e1e4c3ec3e6d]
#    to [9ea33d30cbc295052c1ce443de46ff2974037b13]
# 
============================================================
--- ChangeLog	98a19c78fc79c05644fcf3d868600397997533b3
+++ ChangeLog	3bfb1366ba32a5dee36ab5542a74c36831cf18d0
@@ -1,5 +1,8 @@
 2006-03-12  Matthew Gregan  <address@hidden>
 
+	* configure.ac: Add a second sync_for_stdio test to work around a
+	bug in OS X.
+
 	* testsuite.at: Changes to Perl and Python UNB64_COMMAND
 	invocations to work around some quoting issues broken/revealed in
 	my last change.
============================================================
--- configure.ac	0bbe01c42c3d25e72176fda5c606e1e4c3ec3e6d
+++ configure.ac	9ea33d30cbc295052c1ce443de46ff2974037b13
@@ -446,7 +446,8 @@
 
 # Check whether sync_with_stdio(false) run on C++ streams works correctly.
 # It causes strange problems (EOF returned too early) on some versions of
-# MinGW.
+# MinGW and OS X.  The first test is for the MinGW issue, the second for
+# the OS X issue.
 #
 # In order to check for this issue, we first generate a large input file
 # (over 128KB) and then try to read it (using a buffer size over 512
@@ -499,13 +500,69 @@
 ])],
  [if ./conftest$ac_exeext check_it_now <_conftest.dat; then
     AC_MSG_RESULT(yes)
-    AC_DEFINE(SYNC_WITH_STDIO_WORKS, 1,
-              [Define to 1 if sync_with_stdio works fine on C++ streams])
+    ac_cv_sync_with_stdio=yes
   else
     AC_MSG_RESULT(no)
+    ac_cv_sync_with_stdio=no
   fi
   rm -f _conftest.dat])
 
+
+# To check for this issue, we have a writer with a short delay between writes,
+# and a reader who has set sync_with_stdio(false).
+AC_MSG_CHECKING(whether C++ streams support sync_with_stdio 2)
+AC_RUN_IFELSE([AC_LANG_SOURCE([
+#include <cstdlib>
+#include <iostream>
+#ifdef WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#define sleep(x) Sleep((x) * 1000)
+#else
+#include <unistd.h>
+#endif
+
+int
+main(int argc, char * argv[])
+{
+  if (argc == 1)
+    return EXIT_SUCCESS;
+
+  if (argc == 2)
+    {
+      std::cin.sync_with_stdio(false);
+      int length = 0;
+      while (std::cin.good())
+        {
+          char buffer@<:@1024@:>@;
+          (void)std::cin.read(buffer, sizeof(buffer));
+          length += std::cin.gcount();
+        }
+
+      return length == 82 ? EXIT_SUCCESS : EXIT_FAILURE;
+    }
+  else
+    {
+      std::cout << "1234567890123456789012345678901234567890" << std::endl;
+      sleep(1);
+      std::cout << "1234567890123456789012345678901234567890" << std::endl;
+    }
+  return EXIT_SUCCESS;
+}
+])],
+ [if ./conftest$ac_exeext check_it_now please | ./conftest$ac_exeext foo; then
+    AC_MSG_RESULT(yes)
+    ac_cv_sync_with_stdio_2=yes
+  else
+    AC_MSG_RESULT(no)
+    ac_cv_sync_with_stdio_2=no
+  fi])
+
+if test $ac_cv_sync_with_stdio = yes && test $ac_cv_sync_with_stdio_2 = yes; then
+  AC_DEFINE(SYNC_WITH_STDIO_WORKS, 1,
+              [Define to 1 if sync_with_stdio works fine on C++ streams])
+fi
+
 # allow compiling with different flags/optimisation
 # for monotone versus libs, useful for testing.
 # only makes sense if CFLAGS="" or CXXFLAGS=""