Ensure that stderr from shell functions in recipes is synced.

tests/ChangeLog

@@ -1,5 +1,8 @@
 2013-09-21  Paul Smith  <psmith@gnu.org>
 
+	* scripts/features/output-sync: Test shell functions writing to
+	stderr in recipes: ensure it's captured via output-sync.
+
 	* scripts/options/dash-w: Add a test for -w flag.
 
 2013-09-15  Paul Smith  <psmith@gnu.org>

tests/scripts/features/output-sync

@@ -261,5 +261,11 @@ all:
 
 run_make_test(undef, '-j -Otarget', "foobar\ntrue\n");
 
+# Ensure that shell functions inside recipes write stderr to the sync file
+run_make_test(q!
+all: ; @: $(shell echo foo 1>&2)
+!,
+              '-w -Oline', "#MAKE#: Entering directory '#PWD#'\nfoo\n#MAKE#: Leaving directory '#PWD#'\n");
+
 # This tells the test driver that the perl test script executed properly.
 1;