suggested by gort.andres000@gmail.com.
Á != á, so make sure to do a case-sensitive test.
it's hard to resist the urge to do some reformatting of libhtml.  ;-).

Reference: /n/atom/patch/applied2013/htmlentcase
Date: Thu Aug  1 00:32:28 CES 2013
Signed-off-by: quanstro@quanstro.net

--- /sys/src/libhtml/impl.h	Thu Aug  1 00:30:48 2013
+++ /sys/src/libhtml/impl.h	Thu Aug  1 00:30:49 2013
@@ -34,6 +34,7 @@
 extern int		_Strlen(Rune* s);
 extern Rune*	_Strnclass(Rune* s, Rune* cl, int n);
 extern int		_Strncmpci(Rune* s1, int n1, Rune* s2);
+extern int		_Strncmp(Rune* s1, int n1, Rune* s2);
 extern Rune*	_Strndup(Rune* s, int n);
 extern Rune*	_Strnrclass(Rune* s, Rune* cl, int n);
 extern Rune*	_Strrclass(Rune* s, Rune* cl);
@@ -54,7 +55,8 @@
 	int		val;
 };
 
-extern int			_lookup(StringInt* t, int n, Rune* key, int keylen, int* pans);
+extern int	_lookupop(StringInt* t, int n, Rune* key, int keylen, int (*)(Rune*, int, Rune*), int* pans);
+extern int	_lookup(StringInt* t, int n, Rune* key, int keylen, int* pans);
 extern StringInt*	_makestrinttab(Rune** a, int n);
 extern Rune*		_revlookup(StringInt* t, int n, int val);
 
--- /sys/src/libhtml/lex.c	Thu Aug  1 00:30:50 2013
+++ /sys/src/libhtml/lex.c	Thu Aug  1 00:30:52 2013
@@ -1267,7 +1267,7 @@
 			}
 		}
 		if(c >= 256 || c != '=' && !(isalpha(c) || isdigit(c)))
-			fnd = _lookup(chartab, NCHARTAB, buf, k, &ans);
+			fnd = _lookupop(chartab, NCHARTAB, buf, k, _Strncmp, &ans);
 	}
 	if(!fnd) {
 		backup(ts, savei);
--- /sys/src/libhtml/strinttab.c	Thu Aug  1 00:30:53 2013
+++ /sys/src/libhtml/strinttab.c	Thu Aug  1 00:30:53 2013
@@ -9,7 +9,7 @@
 // Array t must be sorted in increasing lexicographic order of key.
 // If found, return corresponding val in *pans.
 int
-_lookup(StringInt* t, int n, Rune* key, int keylen, int* pans)
+_lookupop(StringInt* t, int n, Rune* key, int keylen, int (*cmp)(Rune*, int, Rune*), int* pans)
 {
 	int	min;
 	int	max;
@@ -20,7 +20,7 @@
 	max = n - 1;
 	while(min <= max) {
 		try = (min + max)/2;
-		cmpresult = _Strncmpci(key, keylen, t[try].key);
+		cmpresult = cmp(key, keylen, t[try].key);
 		if(cmpresult > 0)
 			min = try + 1;
 		else if(cmpresult < 0)
@@ -31,6 +31,12 @@
 		}
 	}
 	return 0;
+}
+
+int
+_lookup(StringInt* t, int n, Rune* key, int keylen, int* pans)
+{
+	return _lookupop(t, n, key, keylen, _Strncmpci, pans);
 }
 
 // Return first key in t[0:n] that corresponds to val,
--- /sys/src/libhtml/utils.c	Thu Aug  1 00:30:54 2013
+++ /sys/src/libhtml/utils.c	Thu Aug  1 00:30:55 2013
@@ -324,6 +324,27 @@
 	}
 }
 
+int
+_Strncmp(Rune *s1, int n1, Rune *s2)
+{
+	Rune c1, c2;
+
+	for(;;) {
+		if(n1-- == 0) {
+			if(*s2 == 0)
+				return 0;
+			return -1;
+		}
+		c1 = *s1++;
+		c2 = *s2++;
+		if(c1 != c2) {
+			if(c1 > c2)
+				return 1;
+			return -1;
+		}
+	}
+}
+
 // emalloc and copy
 Rune*
 _Strdup(Rune* s)