Merged revisions 85617-85622,85624,85626-85627,85629,85631,85635-85636,85638-85639,85641-85642 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r85617 | georg.brandl | 2010-10-17 12:09:06 +0200 (So, 17 Okt 2010) | 1 line

  #5212: md5 weaknesses do not affect hmac, so remove the note about that.
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  r85618 | georg.brandl | 2010-10-17 12:14:38 +0200 (So, 17 Okt 2010) | 1 line

  #9086: correct wrong terminology about linking with pythonXY.dll.
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  r85619 | georg.brandl | 2010-10-17 12:15:50 +0200 (So, 17 Okt 2010) | 1 line

  Make file names consistent.
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  r85620 | georg.brandl | 2010-10-17 12:22:28 +0200 (So, 17 Okt 2010) | 1 line

  Remove second parser module example; it referred to non-readily-available example files, and this kind of discovery is much better done with the AST nowadays anyway.
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  r85621 | georg.brandl | 2010-10-17 12:24:54 +0200 (So, 17 Okt 2010) | 1 line

  #9105: move pickle warning to a bit more prominent location.
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  r85622 | georg.brandl | 2010-10-17 12:28:04 +0200 (So, 17 Okt 2010) | 1 line

  #9112: document error() and exit() methods of ArgumentParser.
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  r85624 | georg.brandl | 2010-10-17 12:34:28 +0200 (So, 17 Okt 2010) | 1 line

  Some markup and style fixes in argparse docs.
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  r85626 | georg.brandl | 2010-10-17 12:38:20 +0200 (So, 17 Okt 2010) | 1 line

  #9117: fix syntax for class definition.
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  r85627 | georg.brandl | 2010-10-17 12:44:11 +0200 (So, 17 Okt 2010) | 1 line

  #9138: reword introduction to classes in Python.
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  r85629 | georg.brandl | 2010-10-17 12:51:45 +0200 (So, 17 Okt 2010) | 1 line

  #5962: clarify sys.exit() vs. threads.
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  r85631 | georg.brandl | 2010-10-17 12:53:54 +0200 (So, 17 Okt 2010) | 1 line

  Fix capitalization.
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  r85635 | georg.brandl | 2010-10-17 13:03:22 +0200 (So, 17 Okt 2010) | 1 line

  #5121: fix claims about default values leading to segfaults.
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  r85636 | georg.brandl | 2010-10-17 13:06:14 +0200 (So, 17 Okt 2010) | 1 line

  #9237: document sys.call_tracing().
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  r85638 | georg.brandl | 2010-10-17 13:13:37 +0200 (So, 17 Okt 2010) | 1 line

  Port changes to pickle docs apparently lost in py3k.
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  r85639 | georg.brandl | 2010-10-17 13:23:56 +0200 (So, 17 Okt 2010) | 1 line

  Make twisted example a bit more logical.
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  r85641 | georg.brandl | 2010-10-17 13:29:07 +0200 (So, 17 Okt 2010) | 1 line

  Fix documentation of dis.opmap direction.
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  r85642 | georg.brandl | 2010-10-17 13:36:28 +0200 (So, 17 Okt 2010) | 1 line

  #9730: fix example.
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diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 3997627..e812b85 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -53,6 +53,13 @@
    ``modules.keys()`` only lists the imported modules.)
 
 
+.. function:: call_tracing(func, args)
+
+   Call ``func(*args)``, while tracing is enabled.  The tracing state is saved,
+   and restored afterwards.  This is intended to be called from a debugger from
+   a checkpoint, to recursively debug some other code.
+
+
 .. data:: copyright
 
    A string containing the copyright pertaining to the Python interpreter.
@@ -219,19 +226,25 @@
 
    Exit from Python.  This is implemented by raising the :exc:`SystemExit`
    exception, so cleanup actions specified by finally clauses of :keyword:`try`
-   statements are honored, and it is possible to intercept the exit attempt at an
-   outer level.  The optional argument *arg* can be an integer giving the exit
-   status (defaulting to zero), or another type of object.  If it is an integer,
-   zero is considered "successful termination" and any nonzero value is considered
-   "abnormal termination" by shells and the like.  Most systems require it to be in
-   the range 0-127, and produce undefined results otherwise.  Some systems have a
-   convention for assigning specific meanings to specific exit codes, but these are
-   generally underdeveloped; Unix programs generally use 2 for command line syntax
-   errors and 1 for all other kind of errors.  If another type of object is passed,
-   ``None`` is equivalent to passing zero, and any other object is printed to
-   ``sys.stderr`` and results in an exit code of 1.  In particular,
-   ``sys.exit("some error message")`` is a quick way to exit a program when an
-   error occurs.
+   statements are honored, and it is possible to intercept the exit attempt at
+   an outer level.
+
+   The optional argument *arg* can be an integer giving the exit status
+   (defaulting to zero), or another type of object.  If it is an integer, zero
+   is considered "successful termination" and any nonzero value is considered
+   "abnormal termination" by shells and the like.  Most systems require it to be
+   in the range 0-127, and produce undefined results otherwise.  Some systems
+   have a convention for assigning specific meanings to specific exit codes, but
+   these are generally underdeveloped; Unix programs generally use 2 for command
+   line syntax errors and 1 for all other kind of errors.  If another type of
+   object is passed, ``None`` is equivalent to passing zero, and any other
+   object is printed to :data:`stderr` and results in an exit code of 1.  In
+   particular, ``sys.exit("some error message")`` is a quick way to exit a
+   program when an error occurs.
+
+   Since :func:`exit` ultimately "only" raises an exception, it will only exit
+   the process when called from the main thread, and the exception is not
+   intercepted.
 
 
 .. data:: exitfunc