[PATCH] docs: mention traditional awk limitation

[Eric Blake]

* doc/autoconf.texi (Limitations of Usual Tools) <awk>: Mention
that traditional awk lacks ENVIRON.
Reported by Ralf Wildenhues.

Signed-off-by: Eric Blake <address@hidden>
---

>>> More precisely, does AC_PROG_AWK guarantee us an awk that will
>>> understand ENVIRON?
>>
>> I think so, yes.
>
>After further testing, I'm starting to think so as well.

Does this patch look okay?

 ChangeLog         |    5 +++++
 doc/autoconf.texi |    3 ++-
 2 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 73be221..930a639 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2010-09-07  Eric Blake  <address@hidden>

+       docs: mention traditional awk limitation
+       * doc/autoconf.texi (Limitations of Usual Tools) <awk>: Mention
+       that traditional awk lacks ENVIRON.
+       Reported by Ralf Wildenhues.
+
        docs: mention bash vs. POSIXLY_CORRECT
        * doc/autoconf.texi (Special Shell Variables) <POSIXLY_CORRECT>:
        Document bash behavior.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 15639d9..f88d73c 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -17845,7 +17845,8 @@ Limitations of Usual Tools
 @address@hidden@var{b}:@var{c}}, @address@hidden, @address@hidden@var{b}},
 or @address@hidden@var{b}}.

-Traditional Awk does not support the predefined @code{CONVFMT} variable.
+Traditional Awk does not support the predefined @code{CONVFMT} or
address@hidden variables.

 Traditional Awk supports only the predefined functions @code{exp}, 
@code{index},
 @code{int}, @code{length}, @code{log}, @code{split}, @code{sprintf},
-- 
1.7.2.2