treat anything above 0x7f as an alpha.  unrelatedly, turn on
warnings and error on bad ftune rather than crash.

Reference: /n/sources/patch/applied/eqnrune
Date: Fri Nov 11 17:02:10 CET 2011
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/eqn/text.c	Fri Nov 11 17:00:22 2011
+++ /sys/src/cmd/eqn/text.c	Fri Nov 11 17:00:21 2011
@@ -1,6 +1,7 @@
 #include "e.h"
 #include "y.tab.h"
 #include <ctype.h>
+#include <utf.h>
 
 #define	CSSIZE	1000
 char	cs[CSSIZE+20];	/* text string converted into this */
@@ -42,14 +43,14 @@
 	wchar_t r;
 	int w;
 
-	w = mbtowc(&r, psp, 3);
+	w = mbtowc(&r, psp, UTFmax);
 	if(w == 0){
 		psp++;
 		return 0;
 	}
 	if(w < 0){
 		psp += 1;
-		return 0x80;	/* Plan 9-ism */
+		return Runeerror;	/* Plan 9-ism */
 	}
 	psp += w;
 	return r;
@@ -112,17 +113,13 @@
 	printf(".ds %d \"%s\n", yyval, p);
 }
 
-int isalpharune(int c)
-{
-	return ('a'<=c && c<='z') || ('A'<=c && c<='Z');
-}
-
 int isdigitrune(int c)
 {
 	return ('0'<=c && c<='9');
 }
 
-trans(int c, char *p1)
+int
+trans(int c, char *)
 {
 	int f;
 
--- /sys/src/cmd/eqn/mkfile	Fri Nov 11 17:00:24 2011
+++ /sys/src/cmd/eqn/mkfile	Fri Nov 11 17:00:23 2011
@@ -35,7 +35,7 @@
 CC=pcc
 LD=pcc
 YFLAGS=-d -S
-CFLAGS=-c
+CFLAGS=-w -c
 
 eqn.c:	y.tab.c prevy.tab.h
 	mv y.tab.c $target