From 5969d900088b6f1e5f379d83191765b0636c51a1 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <bonzini@gnu.org>
Date: Sat, 18 Oct 2008 15:08:17 +0200
Subject: [PATCH] Make sure that nested AS_REQUIRE do not lose the desired
 diversion.

* lib/m4sugar/m4sh.m4 (AS_REQUIRE): Expand _m4_divert_desired before
passing it to m4_divert_require, so that its content is not used
anymore.
* tests/m4sh.at (Nested AS_REQUIRE): New testcase.
---
 ChangeLog           |  8 ++++++++
 lib/m4sugar/m4sh.m4 |  5 ++++-
 tests/m4sh.at       | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 50 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 25c8826a..5380a507 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2008-10-18  Paolo Bonzini  <bonzini@gnu.org>
+
+	Make sure that nested AS_REQUIRE do not lose the desired diversion.
+	* lib/m4sugar/m4sh.m4 (AS_REQUIRE): Expand _m4_divert_desired before
+	passing it to m4_divert_require, so that its content is not used
+	anymore.
+	* tests/m4sh.at (Nested AS_REQUIRE): New testcase.
+
 2008-10-18  Eric Blake  <ebb9@byu.net>
 
 	Document bugs in { } handling.
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 75b8d847..fbce0269 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -314,11 +314,14 @@ m4_divert_pop[]dnl
 # given diversion when expanded (required or not).  The expansion
 # goes in the named diversion or an earlier one.
 #
+# Note: we expand _m4_divert_desired before passing it to m4_divert_require,
+# otherwise we would need to use m4_pushdef and m4_popdef instead of
+# simply m4_define.
 m4_defun([AS_REQUIRE],
 [m4_define([_m4_divert_desired], [m4_default_quoted([$3], [M4SH-INIT])])dnl
 m4_if(m4_eval(_m4_divert(_m4_divert_dump) <= _m4_divert(_m4_divert_desired)), 1,
       [m4_require([$1], [$2])],
-      [m4_divert_require([_m4_divert_desired], [$1], [$2])])])
+      [m4_divert_require(_m4_divert(_m4_divert_desired), [$1], [$2])])])
 
 
 # AS_REQUIRE_SHELL_FN(NAME-TO-CHECK, COMMENT, BODY-TO-EXPAND,
diff --git a/tests/m4sh.at b/tests/m4sh.at
index c39c8c1d..75da8a4d 100644
--- a/tests/m4sh.at
+++ b/tests/m4sh.at
@@ -536,6 +536,44 @@ AT_CHECK([./script])
 AT_CLEANUP
 
 
+## ------------------- ##
+## Nested AS_REQUIRE.  ##
+## ------------------- ##
+
+# Hypothesis: M4sh expands the requirements of AS_REQUIRE in the
+# requested diversion, even if other AS_REQUIREs are interleaved.
+
+AT_SETUP([Nested AS@&t@_REQUIRE])
+AT_KEYWORDS([m4sh])
+
+AT_DATA_M4SH([script.as], [[dnl
+AS_INIT
+
+m4_defun([in_fn_diversion], still_in_m4sh_init_fn=yes)
+m4_defun([not_in_fn_diversion], still_in_m4sh_init_fn=no)
+
+m4_defun([NESTED], [nested_require_in_fn_diversion=$still_in_m4sh_init_fn])
+
+m4_defun([OUTER], [AS_REQUIRE([NESTED])dnl
+outer_require_in_fn_diversion=$still_in_m4sh_init_fn])
+
+m4_defun([test_init], [
+AS_REQUIRE([in_fn_diversion], , [M4SH-INIT-FN])
+AS_REQUIRE([OUTER], , [M4SH-INIT-FN])
+AS_REQUIRE([not_in_fn_diversion], , [M4SH-INIT-FN])
+])
+
+test_init
+if test $outer_require_in_fn_diversion != yes; then AS_EXIT([1]); fi
+if test $nested_require_in_fn_diversion != no; then AS_EXIT([1]); fi
+]])
+
+AT_CHECK_M4SH
+AT_CHECK([./script])
+
+AT_CLEANUP
+
+
 ## ------------------------------------ ##
 ## AS_REQUIRE_SHELL_FN and m4_require.  ##
 ## ------------------------------------ ##
-- 
2.47.2