Patch by Thorsten Glaser <tg@mirbsd.org> for mksh <= 36, to solve
some kind of "bug" resulting in command hang in mksh and also high
cpu workload. For more information, please have a look to Red Hat
Bugzilla ID #474115. And this patch is already in upstream version
control system and will be included in upstream's next release.

--- mksh-36/check.t		2008-10-24 23:36:05.000000000 +0200
+++ mksh-36/check.t.alias	2008-12-02 22:36:13.000000000 +0100
@@ -7,7 +7,7 @@
 # http://www.research.att.com/~gsf/public/ifs.sh
 
 expected-stdout:
-	@(#)MIRBSD KSH R36 2008/10/24
+	@(#)MIRBSD KSH R36 2008/10/24 RedHat-1
 description:
 	Check version of shell.
 stdin:
@@ -151,6 +151,20 @@
 	hi
 	there
 ---
+name: alias-9
+description:
+	Check that recursion is detected/avoided in aliases.
+time-limit: 3
+stdin:
+	echo -n >tf
+	alias ls=ls
+	ls
+	echo $(ls)
+	exit 0
+expected-stdout:
+	tf
+	tf
+---
 name: arith-lazy-1
 description:
 	Check that only one side of ternary operator is evaluated
--- mksh-36/lex.c		2008-10-10 23:31:05.000000000 +0200
+++ mksh-36/lex.c.alias		2008-12-02 22:33:53.000000000 +0100
@@ -904,16 +904,24 @@
 				/* prefer functions over aliases */
 				ktdelete(p);
 			else {
-				Source *s;
+				Source *s = source;
 
-				for (s = source; s->type == SALIAS; s = s->next)
+				while (s->flags & SF_HASALIAS)
 					if (s->u.tblp == p)
 						return LWORD;
+					else
+						s = s->next;
 				/* push alias expansion */
 				s = pushs(SALIAS, source->areap);
 				s->start = s->str = p->val.s;
 				s->u.tblp = p;
+				s->flags |= SF_HASALIAS;
 				s->next = source;
+				if (source->type == SEOF) {
+					/* prevent infinite recursion at EOS */
+					source->u.tblp = p;
+					source->flags |= SF_HASALIAS;
+				}
 				source = s;
 				afree(yylval.cp, ATEMP);
 				goto Again;
--- mksh-36/sh.h		2008-10-24 23:36:06.000000000 +0200
+++ mksh-36/sh.h.alias		2008-12-02 22:35:27.000000000 +0100
@@ -102,7 +102,7 @@
 #ifdef EXTERN
 __RCSID("$MirOS: src/bin/mksh/sh.h,v 1.245 2008/10/24 21:35:43 tg Exp $");
 #endif
-#define MKSH_VERSION "R36 2008/10/24"
+#define MKSH_VERSION "R36 2008/10/24 RedHat-1"
 
 #ifndef MKSH_INCLUDES_ONLY
 
@@ -1117,7 +1117,7 @@
 	union {
 		const char **strv; /* string [] */
 		struct shf *shf;   /* shell file */
-		struct tbl *tblp;  /* alias (SALIAS) */
+		struct tbl *tblp;  /* alias (SF_HASALIAS) */
 		char *freeme;	   /* also for SREREAD */
 	} u;
 	int	line;		/* line number */
@@ -1148,6 +1148,7 @@
 #define SF_ALIASEND	BIT(2)	/* faking space at end of alias */
 #define SF_TTY		BIT(3)	/* type == SSTDIN & it is a tty */
 #define SF_FIRST	BIT(4)	/* initial state (to ignore UTF-8 BOM) */
+#define SF_HASALIAS	BIT(5)	/* u.tblp valid (SALIAS, SEOF) */
 
 typedef union {
 	int i;