Fix SF # 641111, Undocumented side effect of eval
Try to clear up confusion about the current globals being copied
into a globals dict passed to eval(). This wording (more or less)
was suggested in bug report. It should probably be made clearer.
Backport candidate.
diff --git a/Doc/lib/libfuncs.tex b/Doc/lib/libfuncs.tex
index d29155d..ea48539 100644
--- a/Doc/lib/libfuncs.tex
+++ b/Doc/lib/libfuncs.tex
@@ -314,7 +314,12 @@
\var{expression} argument is parsed and evaluated as a Python
expression (technically speaking, a condition list) using the
\var{globals} and \var{locals} dictionaries as global and local name
- space. If the \var{locals} dictionary is omitted it defaults to
+ space. If the \var{globals} dictionary is present and lacks
+ '__builtins__', the current globals are copied into \var{globals} before
+ \var{expression} is parsed. This means that \var{expression}
+ normally has full access to the standard
+ \refmodule[builtin]{__builtin__} module and restricted environments
+ are propagated. If the \var{locals} dictionary is omitted it defaults to
the \var{globals} dictionary. If both dictionaries are omitted, the
expression is executed in the environment where \keyword{eval} is
called. The return value is the result of the evaluated expression.