* doc/autoconf.texi: Mention that if (i in a) doesn't work with traditional Awk.

diff --git a/ChangeLog b/ChangeLog
index 737d523ff29ddf6bbaacc5d491a14e77735074c2..1ef52996161e9106d7177f7db27a86022312cd9c 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -4,6 +4,7 @@
        that traditional Awk lacks 3-arg "split".  It has it.
        Mention that FS must be a single character, and a few other
        99-byte limits of traditional Awk.
+       Mention that if (i in a) doesn't work with traditional Awk.
 
 2006-11-18  Paul Eggert  <eggert@cs.ucla.edu>
 

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 06651d305d347da9f6b4c623dff7885efd2e702c..f95d620431d513958b2aead47422c4d2b3033b34 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -13046,23 +13046,26 @@ Traditional Awk supports only the predefined functions @code{exp},
 Traditional Awk @code{getline} is not at all compatible with Posix;
 avoid it.
 
-In traditional Awk, @code{FS} must be a string containing just one
-ordinary character, and similarly for the field-separator argument to
-@code{split}.
+Traditional Awk has @code{for (i in a) @dots{}} but no other uses of the
+@code{in} keyword.  For example, it lacks @code{if (i in a) @dots{}}.
+
+In code portable to both traditional and modern Awk, @code{FS} must be a
+string containing just one ordinary character, and similarly for the
+field-separator argument to @code{split}.
 
 Traditional Awk has a limit of 99
 fields in a record.  You may be able to circumvent this problem by using
 @code{split}.
 
+Traditional Awk has a limit of at most 99 bytes in a number formatted by
+@code{OFMT}; for example, @code{OFMT="%.300e"; print 0.1;} typically
+dumps core.
+
 The original version of Awk had a limit of at most 99 bytes per
 @code{split} field, 99 bytes per @code{substr} substring, and 99 bytes
 per run of non-special characters in a @code{printf} format, but these
 bugs have been fixed on all practical hosts that we know of.
 
-Traditional Awk has a limit of at most 99 bytes in a number formatted by
-@code{OFMT}; for example, @code{OFMT="%.300e"; print 0.1;} will dump
-core.
-
 @item @command{basename}
 @c ---------------------
 @prindex @command{basename}