pwrite: Fix test whether it works and make it work on HP-UX 11.11.

[gnulib.git] / m4 / pwrite.m4

diff --git a/m4/pwrite.m4 b/m4/pwrite.m4
index 7fdd874..b6aecce 100644 (file)
--- a/m4/pwrite.m4
+++ b/m4/pwrite.m4
@@ -1,4 +1,4 @@
-# pwrite.m4 serial 2
+# pwrite.m4 serial 3
 dnl Copyright (C) 2010-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -15,7 +15,8 @@ AC_DEFUN([gl_FUNC_PWRITE],
   AC_CHECK_FUNCS_ONCE([pwrite])
   if test $ac_cv_func_pwrite = yes; then
     dnl On HP-UX 11.11 with _FILE_OFFSET_BITS=64, pwrite() on a file does not
-    dnl fail when an invalid (negative) offset is passed.
+    dnl fail when an invalid (negative) offset is passed and uses an arbitrary
+    dnl offset instead of the argument.
     AC_CACHE_CHECK([whether pwrite works],
       [gl_cv_func_pwrite_works],
       [
@@ -32,7 +33,7 @@ changequote([,])dnl
         CPPFLAGS="$CPPFLAGS -D_FILE_OFFSET_BITS=64"
         rm -f conftest.out
         AC_RUN_IFELSE(
-          [AC_LANG_SOURCE([[
+          [AC_LANG_PROGRAM([[
 #include <sys/types.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -47,6 +48,43 @@ changequote([,])dnl
     if (pwrite (fd, "b", 1, (off_t) -1) >= 0)
       return 2;
   }
+  /* This test fails on HP-UX 11.00..11.11.  */
+  {
+    int fd;
+    char buf[] = "01";
+
+    fd = open ("conftest.out", O_WRONLY | O_CREAT | O_TRUNC, 0600);
+    if (fd < 0)
+      return 3;
+    if (write (fd, buf, 2) < 2)
+      return 4;
+    if (close (fd) < 0)
+      return 5;
+
+    fd = open ("conftest.out", O_WRONLY, 0600);
+    if (fd < 0)
+      return 6;
+    if (pwrite (fd, "W", 1, (off_t) 0) != 1)
+      return 7;
+    if (close (fd) < 0)
+      return 8;
+
+    fd = open ("conftest.out", O_RDONLY);
+    if (fd < 0)
+      return 9;
+    if (read (fd, buf, 2) < 2)
+      return 10;
+    if (close (fd) < 0)
+      return 11;
+    if (buf[0] != 'W')
+      return 12;
+    if (buf[1] != '1')
+      return 13;
+  }
+  return 0;
+}
+
+
   return 0;
 }]])],
           [gl_cv_func_pwrite_works=yes],