I thought of making COMSUB pass a pointer to the struct op *t->left around

instead, but the parser for the so-called “backticks” (U+0060) still emits
plaintext COMSUB wdstrings, and the evaluation code emits plaintext if the
code is not run (‘-n’ option), so it’s not worth the effort and memory ma-
nagement issues, even though it _would_ optimise the most common case…

Bump version numbers, sync regression tests; add one testcase from the old
webpages too. Sync manpage, this now works, but keep the workaround in, as
“portability issue” with slightly changed wording.

Also, /bin/sleep must be used in one manpage example if sleep is built in.

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.413 2011/02/27 19:41:17 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.414 2011/03/06 01:50:08 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 $
@@ -25,7 +25,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R39 2011/02/18
+	@(#)MIRBSD KSH R39 2011/03/05
 description:
 	Check version of shell.
 stdin:
@@ -6933,11 +6933,10 @@ expected-stdout:
 ---
 name: comsub-1
 description:
-	COMSUB are currently parsed by hacking lex.c instead of
+	COMSUB are now parsed recursively, so this works
-	recursively (see regression-6): matching parenthesēs bug
+	see also regression-6: matching parenthesēs bug
-	Fails on: pdksh mksh bash2 bash3 zsh
+	Fails on: pdksh bash2 bash3 zsh
-	Passes on: bash4 ksh93
+	Passes on: bash4 ksh93 mksh(20110305+)
-expected-fail: yes
 stdin:
 	echo $(case 1 in (1) echo yes;; (2) echo no;; esac)
 	echo $(case 1 in 1) echo yes;; 2) echo no;; esac)
@@ -6949,10 +6948,9 @@ name: comsub-2
 description:
 	RedHat BZ#496791 – another case of missing recursion
 	in parsing COMSUB expressions
-	Fails on: pdksh mksh bash2 bash3¹ bash4¹ zsh
+	Fails on: pdksh bash2 bash3¹ bash4¹ zsh
-	Passes on: ksh93
+	Passes on: ksh93 mksh(20110305+)
 	① bash[34] seem to choke on comment ending with backslash-newline
-expected-fail: yes
 stdin:
 	# a comment with " ' \
 	x=$(
@@ -6963,6 +6961,24 @@ stdin:
 expected-stdout:
 	yes
 ---
+name: comsub-3
+description:
+	Extended test for COMSUB explaining why a recursive parser
+	is a must (a non-recursive parser cannot pass all three of
+	these test cases, especially the ‘#’ is difficult)
+stdin:
+	echo $(typeset -i10 x=16#20; echo $x)
+	echo $(typeset -Uui16 x=16#$(id -u)
+	) .
+	echo $(c=1; d=1
+	typeset -Uui16 a=36#foo; c=2
+	typeset -Uui16 b=36 #foo; d=2
+	echo $a $b $c $d)
+expected-stdout:
+	32
+	.
+	16#4F68 16#24 2 1
+---
 name: test-stnze-1
 description:
 	Check that the short form [ $x ] works

mksh.1

@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.251 2011/02/18 22:26:11 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.252 2011/03/06 01:50:09 tg Exp $
 .\" $OpenBSD: ksh.1,v 1.138 2010/09/20 07:41:17 jmc Exp $
 .\"-
 .\" Copyright © 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
@@ -72,7 +72,7 @@
 .\" with -mandoc, it might implement .Mx itself, but we want to
 .\" use our own definition. And .Dd must come *first*, always.
 .\"
-.Dd $Mdocdate: February 18 2011 $
+.Dd $Mdocdate: March 6 2011 $
 .\"
 .\" Check which macro package we use
 .\"
@@ -1238,12 +1238,23 @@ Note that
 has the same effect as
 .Ic $(cat foo) .
 .Pp
-.Sy Note :
+Note that some shells do not use a recursive parser for command substitutions,
-.Pf $( Ns Ar command Ns \&)
+leading to failure for certain constructs; to be portable, use as workaround
-expressions are currently parsed by finding matching parentheses,
+.Ql x=$(cat) \*(Lt\*(Lt"EOF"
-regardless of quoting; comments containing quote characters are
+(or the newline-keeping
-not handled correctly.
+.Ql x=\*(Lt\*(Lt"EOF"
-This should be fixed soon.
+extension) instead to merely slurp the string.
+.St -p1003.1
+recommends to use case statements of the form
+.Ql "x=$(case $foo in (bar) echo $bar ;; (*) echo $baz ;; esac)"
+instead, which would work but not serve as example for this portability issue.
+.Bd -literal -offset indent
+x=$(case $foo in bar) echo $bar ;; *) echo $baz ;; esac)
+# above fails to parse on old shells; below is the workaround
+x=$(eval $(cat)) \*(Lt\*(Lt"EOF"
+case $foo in bar) echo $bar ;; *) echo $baz ;; esac
+EOF
+.Ed
 .Pp
 Arithmetic substitutions are replaced by the value of the specified expression.
 For example, the command
@@ -6107,28 +6118,7 @@ the currently running part of the pipeline; in this example,
 is immediately printed on suspension (but not later after an
 .Ic fg ) .
 .Bd -literal -offset indent
-$ sleep 666 && echo fubar
+$ /bin/sleep 666 && echo fubar
-.Ed
-.Pp
-Some parts of the parser are not recursive; the following
-code fails because of the parenthesis asymmetry
-.Pq RedHat BZ#496791 .
-A workaround exists; use
-.Ql x=$(cat) \*(Lt\*(Lt"EOF"
-or the newline-keeping
-.Ql x=\*(Lt\*(Lt"EOF"
-instead to merely slurp the string.
-Of course, in this case, the form
-.Ql x=$(case $foo in (bar) ...
-actually recommended by
-.St -p1003.1
-would work as well, but we use it as an example of this parser bug.
-.Bd -literal -offset indent
-x=$(case $foo in bar) echo $bar ;; *) echo $baz ;; esac)
-# above fails to parse; below is the workaround
-x=$(eval $(cat)) \*(Lt\*(Lt"EOF"
-case $foo in bar) echo $bar ;; *) echo $baz ;; esac
-EOF
 .Ed
 .Pp
 This document attempts to describe

sh.h

@@ -154,9 +154,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.436 2011/03/06 01:25:33 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.437 2011/03/06 01:50:11 tg Exp $");
 #endif
-#define MKSH_VERSION "R39 2011/02/18"
+#define MKSH_VERSION "R39 2011/03/05"
 
 #ifndef MKSH_INCLUDES_ONLY