emacs: Fix crash on inputting Asian chars (Solaris 240-22461939)

This change is pulled from here:
https://github.com/oracle/solaris-userland/blob/master/components/ksh93/patches/240-22461939.patch

Information:
att#6

George Lijo wrote on 14 Mar 2016:
> I observed this issue in a Solaris 11 system on ksh2012-08-01
> [...]. The issue can be reproduced if we add Asian locales to
> ibus (such as Korean). In the ksh93 shell prompt, input some
> Asian character. ksh promptly dumps core [...].
>
> The coredump happens at the following line no 320 in
> src/cmd/ksh93/edit/emacs.c
>	if(c!='\t' && c!=ESC && !isdigit(c)).
>
> I referred the vi.c code and added the digit(c) macro, i.e.
> ((c&~STRIP)==0 && isdigit(c)) and replaced the isdigit(c) usage
> with the "digit(c)" macro.

src/cmd/ksh93/edit/emacs.c

@@ -90,13 +90,15 @@ One line screen editor for any program
     static int	print(int);
     static int	_isword(int);
 #   define  isword(c)	_isword(out[c])
+#   define digit(c)	((c&~STRIP)==0 && isdigit(c))
 
 #else
 #   define gencpy(a,b)	strcpy((char*)(a),(char*)(b))
 #   define genncpy(a,b,n)	strncpy((char*)(a),(char*)(b),n)
 #   define genlen(str)	strlen(str)
 #   define print(c)	isprint(c)
 #   define isword(c)	(isalnum(out[c]) || (out[c]=='_'))
+#   define digit(c)	isdigit(c)
 #endif /*SHOPT_MULTIBYTE */
 
 typedef struct _emacs_
@@ -323,7 +325,7 @@ int ed_emacsread(void *context, int fd,char *buff,int scend, int reedit)
 			count = 1;
 		adjust = -1;
 		i = cur;
-		if(c!='\t' && c!=ESC && !isdigit(c))
+		if(c!='\t' && c!=ESC && !digit(c))
 			ep->ed->e_tabcount = 0;
 		switch(c)
 		{
@@ -782,7 +784,7 @@ static int escape(register Emacs_t* ep,register genchar *out,int count)
 	int digit,ch;
 	digit = 0;
 	value = 0;
-	while ((i=ed_getchar(ep->ed,0)),isdigit(i))
+	while ((i=ed_getchar(ep->ed,0)),digit(i))
 	{
 		value *= 10;
 		value += (i - '0');
@@ -1020,7 +1022,7 @@ static int escape(register Emacs_t* ep,register genchar *out,int count)
 				{
 					i=ed_getchar(ep->ed,0);
 					ed_ungetchar(ep->ed,i);
-					if(isdigit(i))
+					if(digit(i))
 						ed_ungetchar(ep->ed,ESC);
 				}
 			}