Merged revisions 66703,66708 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk

........
  r66703 | gregory.p.smith | 2008-09-30 15:41:13 -0500 (Tue, 30 Sep 2008) | 6 lines

  Works around issue3863: freebsd4/5/6 and os2emx are known to have OS bugs when
  calling fork() from a child thread.  This disables that unit test (with a note
  printed to stderr) on those platforms.

  A caveat about buggy platforms is added to the os.fork documentation.
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  r66708 | andrew.macintyre | 2008-09-30 22:25:25 -0500 (Tue, 30 Sep 2008) | 9 lines

  fix for issue 3862: test_array fails FreeBSD 7 amd64

  FreeBSD 7's underlying malloc() is behaves differently to earlier versions
  and seriously overcommits available memory on amd64.  This may affect
  other 64bit platforms in some circumstances, so the scale of the
  problematic test is wound back.

  Patch by Mark Dickinson, reviewed by Martin von Loewis.
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diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 82a5b98..81a3f35 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -1389,6 +1389,10 @@
 
    Fork a child process.  Return ``0`` in the child and the child's process id in the
    parent.  If an error occurs :exc:`OSError` is raised.
+
+   Note that some platforms including FreeBSD <= 6.3, Cygwin and OS/2 EMX have
+   known issues when using fork() from a thread.
+
    Availability: Unix.