while testing haserl-0.9.26 on MirBSD, I discovered that the echo builtin

in FSH mode did in fact, contrary to POSIX and Debian Policy 10.4 behavi-
our (I think), interpret escape sequences; fix and add testsuite for echo

check.t

@@ -1,4 +1,4 @@
-# $MirOS: src/bin/mksh/check.t,v 1.320 2009/10/10 17:39:48 tg Exp $
+# $MirOS: src/bin/mksh/check.t,v 1.321 2009/10/10 21:17:28 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 2009/10/04
+	@(#)MIRBSD KSH R39 2009/10/10
 description:
 	Check version of shell.
 stdin:
@@ -6571,3 +6571,22 @@ stdin:
 expected-stdout:
 	fxbar 0
 ---
+name: echo-test-1
+description:
+	Test what the echo builtin does (mksh)
+stdin:
+	echo -n 'foo\x40bar'
+	echo -e '\tbaz'
+expected-stdout:
+	foo@bar	baz
+---
+name: echo-test-2
+description:
+	Test what the echo builtin does (POSIX)
+arguments: !-o!sh!
+stdin:
+	echo -n 'foo\x40bar'
+	echo -e '\tbaz'
+expected-stdout:
+	foo\x40bar-e \tbaz
+---

funcs.c

@@ -25,7 +25,7 @@
 
 #include "sh.h"
 
-__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.136 2009/10/02 18:08:33 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/funcs.c,v 1.137 2009/10/10 21:17:29 tg Exp $");
 
 #if HAVE_KILLPG
 /*
@@ -507,31 +507,38 @@ c_print(const char **wp)
 #define PO_PMINUSMINUS	BIT(2)	/* print a -- argument */
 #define PO_HIST		BIT(3)	/* print to history instead of stdout */
 #define PO_COPROC	BIT(4)	/* printing to coprocess: block SIGPIPE */
-	int fd = 1;
+	int fd = 1, c;
 	int flags = PO_EXPAND|PO_NL;
 	const char *s, *emsg;
 	XString xs;
 	char *xp;
 
-	if (wp[0][0] == 'e') {	/* echo command */
+	if (wp[0][0] == 'e') {
-		int nflags = flags;
+		/* echo builtin */
-
+		wp++;
-		/* A compromise between sysV and BSD echo commands:
-		 * escape sequences are enabled by default, and
-		 * -n, -e and -E are recognised if they appear
-		 * in arguments with no illegal options (ie, echo -nq
-		 * will print -nq).
-		 * Different from sysV echo since options are recognised,
-		 * different from BSD echo since escape sequences are enabled
-		 * by default.
-		 */
-		wp += 1;
 		if (Flag(FSH)) {
-			if (*wp && strcmp(*wp, "-n") == 0) {
+			/* Debian Policy 10.4 compliant "echo" builtin */
-				flags &= ~PO_NL;
+			if (*wp && !strcmp(*wp, "-n")) {
+				/* we recognise "-n" only as the first arg */
+				flags = 0;
 				wp++;
-			}
+			} else
-		} else
+				/* otherwise, we print everything as-is */
+				flags = PO_NL;
+		} else {
+			int nflags = flags;
+
+			/**
+			 * a compromise between sysV and BSD echo commands:
+			 * escape sequences are enabled by default, and -n,
+			 * -e and -E are recognised if they appear in argu-
+			 * ments with no illegal options (ie, echo -nq will
+			 * print -nq).
+			 * Different from sysV echo since options are reco-
+			 * gnised, different from BSD echo since escape se-
+			 * quences are enabled by default.
+			 */
+
 			while ((s = *wp) && *s == '-' && s[1]) {
 				while (*++s)
 					if (*s == 'n')
@@ -546,14 +553,17 @@ c_print(const char **wp)
 						 * nflags, print argument
 						 */
 						break;
+
 				if (*s)
 					break;
 				wp++;
 				flags = nflags;
 			}
+		}
 	} else {
 		int optc;
 		const char *opts = "Rnprsu,";
+
 		while ((optc = ksh_getopt(wp, &builtin_opt, opts)) != -1)
 			switch (optc) {
 			case 'R': /* fake BSD echo command */
@@ -590,6 +600,7 @@ c_print(const char **wp)
 			case '?':
 				return (1);
 			}
+
 		if (!(builtin_opt.info & GI_MINUSMINUS)) {
 			/* treat a lone - like -- */
 			if (wp[builtin_opt.optind] &&
@@ -603,7 +614,6 @@ c_print(const char **wp)
 	Xinit(xs, xp, 128, ATEMP);
 
 	while (*wp != NULL) {
-		int c;
 		s = *wp;
 		while ((c = *s++) != '\0') {
 			Xcheck(xs, xp);
@@ -649,7 +659,7 @@ c_print(const char **wp)
 		histsave(&source->line, Xstring(xs, xp), true, false);
 		Xfree(xs, xp);
 	} else {
-		int n, len = Xlength(xs, xp);
+		int len = Xlength(xs, xp);
 		int opipe = 0;
 
 		/* Ensure we aren't killed by a SIGPIPE while writing to
@@ -662,8 +672,7 @@ c_print(const char **wp)
 			opipe = block_pipe();
 		}
 		for (s = Xstring(xs, xp); len > 0; ) {
-			n = write(fd, s, len);
+			if ((c = write(fd, s, len)) < 0) {
-			if (n < 0) {
 				if (flags & PO_COPROC)
 					restore_pipe(opipe);
 				if (errno == EINTR) {
@@ -675,8 +684,8 @@ c_print(const char **wp)
 				}
 				return (1);
 			}
-			s += n;
+			s += c;
-			len -= n;
+			len -= c;
 		}
 		if (flags & PO_COPROC)
 			restore_pipe(opipe);

mksh.1

@@ -1,4 +1,4 @@
-.\" $MirOS: src/bin/mksh/mksh.1,v 1.193 2009/10/02 18:08:35 tg Exp $
+.\" $MirOS: src/bin/mksh/mksh.1,v 1.194 2009/10/10 21:17:30 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
@@ -48,7 +48,7 @@
 .el .xD \\$1 \\$2 \\$3 \\$4 \\$5 \\$6 \\$7 \\$8
 ..
 .\"-
-.Dd $Mdocdate: October 2 2009 $
+.Dd $Mdocdate: October 10 2009 $
 .Dt MKSH 1
 .Os MirBSD
 .Sh NAME
@@ -2694,7 +2694,7 @@ assignments are performed and exported for the duration of the command.
 .Pp
 The following describes the special and regular built-in commands:
 .Pp
-.Bl -tag -width Ds -compact
+.Bl -tag -width false -compact
 .It Ic \&. Ar file Op Ar arg ...
 This is called the
 .Dq dot
@@ -3034,6 +3034,8 @@ If the
 option is set, only the first argument is treated as an option, and only
 if it is exactly
 .Dq Fl n .
+Backslash interpretation is disabled.
+.Pp
 .It Ic eval Ar command ...
 The arguments are concatenated (with spaces between them) to form a single
 string which the shell then parses and executes in the current environment.

sh.h

@@ -134,9 +134,9 @@
 #endif
 
 #ifdef EXTERN
-__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.353 2009/10/04 13:19:33 tg Exp $");
+__RCSID("$MirOS: src/bin/mksh/sh.h,v 1.354 2009/10/10 21:17:31 tg Exp $");
 #endif
-#define MKSH_VERSION "R39 2009/10/04"
+#define MKSH_VERSION "R39 2009/10/10"
 
 #ifndef MKSH_INCLUDES_ONLY