read builtin: Empty variables on timeout

This matches how a non-timeout error is handled.

Reviewed by:	jilles
MFC after:	2 weeks
Differential Revision: https://reviews.freebsd.org/D31876

3 files changed, 27 insertions, 0 deletions

diff --git a/bin/sh/tests/builtins/Makefile b/bin/sh/tests/builtins/Makefile
index 197d735920e6..f9b464a6da4b 100644
--- a/bin/sh/tests/builtins/Makefile
+++ b/bin/sh/tests/builtins/Makefile
@@ -141,6 +141,8 @@ ${PACKAGE}FILES+=		read6.0
 ${PACKAGE}FILES+=		read7.0
 ${PACKAGE}FILES+=		read8.0
 ${PACKAGE}FILES+=		read9.0
+${PACKAGE}FILES+=		read10.0
+${PACKAGE}FILES+=		read11.0
 ${PACKAGE}FILES+=		return1.0
 ${PACKAGE}FILES+=		return2.1
 ${PACKAGE}FILES+=		return3.1
diff --git a/bin/sh/tests/builtins/read10.0 b/bin/sh/tests/builtins/read10.0
new file mode 100644
index 000000000000..5fc19896390a
--- /dev/null
+++ b/bin/sh/tests/builtins/read10.0
@@ -0,0 +1,8 @@
+
+set -e
+
+v=original_value
+r=0
+read v < /dev/null || r=$?
+[ "$r" -eq 1 ]
+[ -z "$v" ]
diff --git a/bin/sh/tests/builtins/read11.0 b/bin/sh/tests/builtins/read11.0
new file mode 100644
index 000000000000..c75ed9c92a83
--- /dev/null
+++ b/bin/sh/tests/builtins/read11.0
@@ -0,0 +1,17 @@
+
+set -e
+
+T=$(mktemp -d ${TMPDIR:-/tmp}/sh-test.XXXXXX)
+trap 'rm -rf "$T"' 0
+cd $T
+mkfifo fifo1
+# Open fifo1 for writing and then read block on a dummy fifo
+{ mkfifo fifo2; read dummy <fifo2; } >fifo1 &
+# Wait for the child to open fifo1 for writing
+exec 3<fifo1
+v=original_value
+r=0
+read -t 0 v <&3 || r=$?
+kill -TERM "$!" || :
+{ [ "$r" -gt 128 ] && [ "$(kill -l "$r")" = ALRM ]; } || exit
+[ -z "$v" ]