allow “function stop () {” (bashism, an evil one)

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.305 2009/09/07 17:24:47 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.306 2009/09/19 18:36:57 tg Exp $
 # $OpenBSD: bksl-nl.t,v 1.2 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: history.t,v 1.5 2001/01/28 23:04:56 niklas Exp $
 # $OpenBSD: read.t,v 1.3 2003/03/10 03:48:16 david Exp $
@@ -5256,6 +5256,33 @@ expected-stdout:
 	bar
 	rab
 ---
+name: bash-function-parens
+description:
+	ensure the keyword function is ignored when preceding
+	POSIX style function declarations (bashism)
+stdin:
+	mk() {
+		echo '#!'"$__progname"
+		echo "$1 {"
+		echo '	echo "bar='\''$0'\'\"
+		echo '}'
+		echo ${2:-foo}
+	}
+	mk 'function foo' >f-korn
+	mk 'foo ()' >f-dash
+	mk 'function foo ()' >f-bash
+	mk 'function stop ()' stop >f-stop
+	chmod +x f-*
+	echo "korn: $(./f-korn)"
+	echo "dash: $(./f-dash)"
+	echo "bash: $(./f-bash)"
+	echo "stop: $(./f-stop)"
+expected-stdout:
+	korn: bar='foo'
+	dash: bar='./f-dash'
+	bash: bar='./f-bash'
+	stop: bar='./f-stop'
+---
 name: integer-base-one-1
 description:
 	check if the use of fake integer base 1 works

mksh.1

@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.185 2009/09/19 15:16:04 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.186 2009/09/19 18:36:58 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.129 2009/05/28 06:09:06 jmc Exp $
 .\"-
 .\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
@@ -749,6 +749,15 @@ below).
 Whitespace (space or tab) after
 .Ar name
 will be ignored most of the time.
+.It Xo function Ar name Ns ()
+.No { Ar list ; No }
+.Xc
+The same as
+.Ar name Ns ()
+.Pq Nm bash Ns ism .
+The
+.Ic function
+keyword is ignored.
 .It Xo Ic time Op Fl p
 .Op Ar pipeline
 .Xc

syn.c

@@ -22,7 +22,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/syn.c,v 1.41 2009/08/28 20:30:59 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/syn.c,v 1.42 2009/09/19 18:36:59 tg Exp $");
 
 struct nesting_state {
 	int start_token;	/* token than began nesting (eg, FOR) */
@@ -41,7 +41,7 @@ static struct op *thenpart(void);
 static struct op *elsepart(void);
 static struct op *caselist(void);
 static struct op *casepart(int);
-static struct op *function_body(char *, int);
+static struct op *function_body(char *, bool);
 static char **wordlist(void);
 static struct op *block(int, struct op *, struct op *, char **);
 static struct op *newtp(int);
@@ -595,7 +595,7 @@ casepart(int endtok)
 
 static struct op *
 function_body(char *name,
-    int ksh_func)		/* function foo { ... } vs foo() { .. } */
+    bool ksh_func)		/* function foo { ... } vs foo() { .. } */
 {
 	char *sname, *p;
 	struct op *t;
@@ -612,21 +612,32 @@ function_body(char *name,
 		if (ctype(*p, C_QUOTE) || *p == '=')
 			yyerror("%s: invalid function name\n", sname);
 
-	t = newtp(TFUNCT);
-	t->str = sname;
-	t->u.ksh_func = ksh_func;
-	t->lineno = source->line;
-
 	/* Note that POSIX allows only compound statements after foo(), sh and
 	 * AT&T ksh allow any command, go with the later since it shouldn't
 	 * break anything. However, for function foo, AT&T ksh only accepts
 	 * an open-brace.
 	 */
 	if (ksh_func) {
+		if (tpeek(CONTIN|KEYWORD|ALIAS) == '(' /* ) */) {
+			struct tbl *tp;
+
+			/* function foo () { */
+			ACCEPT;
+			musthave(')', 0);
+			/* degrade to POSIX function */
+			ksh_func = false;
+			if ((tp = ktsearch(&aliases, sname, hash(sname))))
+				ktdelete(tp);
+		}
 		musthave('{', CONTIN|KEYWORD|ALIAS); /* } */
 		REJECT;
 	}
 
+	t = newtp(TFUNCT);
+	t->str = sname;
+	t->u.ksh_func = ksh_func;
+	t->lineno = source->line;
+
 	old_func_parse = e->flags & EF_FUNC_PARSE;
 	e->flags |= EF_FUNC_PARSE;
 	if ((t->left = get_command(CONTIN)) == NULL) {