sh: Improve the command builtin:

* avoid unnecessary fork
* allow executing builtins via command
* executing a special builtin via command removes its special properties

Obtained from:	NetBSD (parts)

2 files changed, 100 insertions, 0 deletions

diff --git a/tools/regression/bin/sh/builtins/command8.0 b/tools/regression/bin/sh/builtins/command8.0
new file mode 100644
index 0000000..949ffed
--- /dev/null
+++ b/tools/regression/bin/sh/builtins/command8.0
@@ -0,0 +1,45 @@
+# $FreeBSD$
+IFS=,
+
+SPECIAL="break,\
+	:,\
+	continue,\
+	. /dev/null,\
+	eval,\
+	exec,\
+	export -p,\
+	readonly -p,\
+	set,\
+	shift 0,\
+	times,\
+	trap,\
+	unset foo"
+
+set -e
+
+# Check that special builtins can be executed via "command".
+
+set -- ${SPECIAL}
+for cmd in "$@"
+do
+	sh -c "v=:; while \$v; do v=false; command ${cmd}; done" >/dev/null
+done
+
+while :; do
+	command break
+	echo Error on line $LINENO
+done
+
+set p q r
+command shift 2
+if [ $# -ne 1 ]; then
+	echo Error on line $LINENO
+fi
+
+(
+	command exec >/dev/null
+	echo Error on line $LINENO
+)
+
+set +e
+! command shift 2 2>/dev/null
diff --git a/tools/regression/bin/sh/builtins/var-assign2.0 b/tools/regression/bin/sh/builtins/var-assign2.0
new file mode 100644
index 0000000..8485df8
--- /dev/null
+++ b/tools/regression/bin/sh/builtins/var-assign2.0
@@ -0,0 +1,55 @@
+# $FreeBSD$
+IFS=,
+
+SPECIAL="break,\
+	:,\
+	continue,\
+	. /dev/null,\
+	eval,\
+	exec,\
+	export -p,\
+	readonly -p,\
+	set,\
+	shift 0,\
+	times,\
+	trap,\
+	unset foo"
+
+UTILS="alias,\
+	bg,\
+	bind,\
+	cd,\
+	command echo,\
+	echo,\
+	false,\
+	fc -l,\
+	fg,\
+	getopts a var,\
+	hash,\
+	jobs,\
+	printf a,\
+	pwd,\
+	read var < /dev/null,\
+	test,\
+	true,\
+	type ls,\
+	ulimit,\
+	umask,\
+	unalias -a,\
+	wait"
+
+set -e
+
+# With 'command', variable assignments affect the shell environment.
+
+set -- ${SPECIAL}
+for cmd in "$@"
+do
+	sh -c "VAR=0; VAR=1 command ${cmd}; exit \${VAR}" >/dev/null 2>&1
+done
+
+set -- ${UTILS}
+for cmd in "$@"
+do
+	sh -c "VAR=0; VAR=1 command ${cmd}; exit \${VAR}" >/dev/null 2>&1
+done