--- a/client.mk
+++ b/client.mk
@@ -305,17 +305,17 @@ EXTRA_CONFIG_DEPS := \
   $(TOPSRCDIR)/old-configure.in \
   $(wildcard $(TOPSRCDIR)/build/autoconf/*.m4) \
   $(TOPSRCDIR)/js/src/aclocal.m4 \
   $(TOPSRCDIR)/js/src/old-configure.in \
   $(NULL)
 
 $(CONFIGURES): %: %.in $(EXTRA_CONFIG_DEPS)
 	@echo Generating $@
-	sed '1,/^divert/d' $< > $@
+	cp -f $< $@
 	chmod +x $@
 
 CONFIG_STATUS_DEPS := \
   $(wildcard $(TOPSRCDIR)/*/confvars.sh) \
   $(CONFIGURES) \
   $(TOPSRCDIR)/CLOBBER \
   $(TOPSRCDIR)/nsprpub/configure \
   $(TOPSRCDIR)/config/milestone.txt \

--- a/configure.in
+++ b/configure.in
@@ -1,24 +1,25 @@
-dnl This Source Code Form is subject to the terms of the Mozilla Public
-dnl License, v. 2.0. If a copy of the MPL was not distributed with this
-dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
-dnl
-dnl Welcome to the new world of configure. We're working on moving to a
-dnl python based configure. In the meanwhile, remains of the old autoconf
-dnl based configure is in old-configure.in.
-dnl If you need to add something, please come talk to the build system
-dnl peers for now.
-dnl
-dnl Because adding a configure file in the tree is going to conflict with
-dnl existing configure files in people's (and automation) work trees, and
-dnl because some automation jobs are still running autoconf and configure
-dnl "manually", this file is actually an m4 file that is processed by
-dnl autoconf, but doesn't call any autoconf macros. The `divert` line
-dnl below ensures the script that follows is output by autoconf.
-divert(0)dnl
+#!/bin/sh
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Welcome to the new world of configure. We're working on moving to a
+# python based configure. In the meanwhile, remains of the old autoconf
+# based configure is in old-configure.in.
+# If you need to add something, please come talk to the build system
+# peers for now.
+#
+# Because adding a configure file in the tree is going to conflict with
+# existing configure files in people's (and automation) work trees, and
+# because some automation jobs are still running autoconf and configure
+# "manually", this file is actually an m4 file that is processed by
+# autoconf, but doesn't call any autoconf macros. The `divert` line
+# below ensures the script that follows is output by autoconf.
+: "divert(0)dnl"
 #!/bin/sh
 
 SRCDIR=$(dirname $0)
 TOPSRCDIR="$SRCDIR"
 export OLD_CONFIGURE="$SRCDIR"/old-configure
 
 which python2.7 > /dev/null && exec python2.7 "$TOPSRCDIR/configure.py" "$@" || exec python "$TOPSRCDIR/configure.py" "$@"

--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -1,25 +1,26 @@
-dnl This Source Code Form is subject to the terms of the Mozilla Public
-dnl License, v. 2.0. If a copy of the MPL was not distributed with this
-dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
-dnl
-dnl Welcome to the new world of configure. We're working on moving to a
-dnl python based configure. In the meanwhile, remains of the old autoconf
-dnl based configure is in old-configure.in.
-dnl If you need to add something, please come talk to the build system
-dnl peers for now.
-dnl
-dnl Because adding a configure file in the tree is going to conflict with
-dnl existing configure files in people's (and automation) work trees, and
-dnl because some automation jobs are still running autoconf and configure
-dnl "manually", this file is actually an m4 file that is processed by
-dnl autoconf, but doesn't call any autoconf macros. The `divert` line
-dnl below ensures the script that follows is output by autoconf.
-divert(0)dnl
+#!/bin/sh
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Welcome to the new world of configure. We're working on moving to a
+# python based configure. In the meanwhile, remains of the old autoconf
+# based configure is in old-configure.in.
+# If you need to add something, please come talk to the build system
+# peers for now.
+#
+# Because adding a configure file in the tree is going to conflict with
+# existing configure files in people's (and automation) work trees, and
+# because some automation jobs are still running autoconf and configure
+# "manually", this file is actually an m4 file that is processed by
+# autoconf, but doesn't call any autoconf macros. The `divert` line
+# below ensures the script that follows is output by autoconf.
+: "divert(0)dnl"
 #!/bin/sh
 
 SRCDIR=$(dirname $0)
 TOPSRCDIR="$SRCDIR"/../..
 export OLD_CONFIGURE="$SRCDIR"/old-configure
 
 set -- "$@" --enable-project=js