From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 18 Sep 2022 02:43:46 +0000 (-0700)
Subject: Improve comment in previous change
X-Git-Tag: v2.72c~33
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df62fad153142de953372a5744995ee3bfae5a02;p=thirdparty%2Fautoconf.git

Improve comment in previous change
---

diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index b6714356f..01d3b5d64 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -59,6 +59,10 @@
 # DIVERSION-NAME which is supposed to be an actual diversion number.
 # Of course it would be nicer to use m4_case here, instead of zillions
 # of little macros, but it then takes twice longer to run 'autoconf'!
+# BINSH is 1, not 0, so that user code can m4_cleardivert([BINSH]) and
+# then generate its own BINSH; m4's special treatment of diversion 0
+# would not allow that if BINSH were 0.  Leave an undocumented gap
+# between BINSH and HEADER-REVISION for possible future extensions.
 m4_define([_m4_divert(BINSH)],             1)
 m4_define([_m4_divert(HEADER-REVISION)],   3)
 m4_define([_m4_divert(HEADER-COMMENT)],    4)