This patch fixes a bug on machines where char is unsigned by default, by
extending the type of clifford_max_label to include all 257 possible
return values.

--- ginac-1.4.3.orig/ginac/add.cpp	2008-03-27 10:16:10.000000000 +0000
+++ ginac-1.4.3/ginac/add.cpp	2008-05-03 10:59:02.000000000 +0100
@@ -291,7 +291,7 @@
 {
 	std::auto_ptr<epvector> coeffseq(new epvector);
 	std::auto_ptr<epvector> coeffseq_cliff(new epvector);
-	char rl = clifford_max_label(s);
+	int rl = clifford_max_label(s);
 	bool do_clifford = (rl != -1);
 	bool nonscalar = false;
 
--- ginac-1.4.3.orig/ginac/clifford.cpp	2008-03-27 10:16:10.000000000 +0000
+++ ginac-1.4.3/ginac/clifford.cpp	2008-05-03 10:58:24.000000000 +0100
@@ -1126,7 +1126,7 @@
 	return e1;
 }
 
-char clifford_max_label(const ex & e, bool ignore_ONE)
+int clifford_max_label(const ex & e, bool ignore_ONE)
 {
 	if (is_a<clifford>(e))
 		if (ignore_ONE && is_a<diracone>(e.op(0)))
@@ -1134,7 +1134,7 @@
 		else
 			return ex_to<clifford>(e).get_representation_label();
 	else {
-		char rl = -1;
+		int rl = -1;
 		for (size_t i=0; i < e.nops(); i++) 
 			rl = (rl > clifford_max_label(e.op(i), ignore_ONE)) ? rl : clifford_max_label(e.op(i), ignore_ONE);
 		return rl;
--- ginac-1.4.3.orig/ginac/clifford.h	2008-03-27 10:16:10.000000000 +0000
+++ ginac-1.4.3/ginac/clifford.h	2008-05-03 11:04:08.000000000 +0100
@@ -299,7 +299,7 @@
  *
  *  @param e Expression to be processed
  *  @ignore_ONE defines if clifford_ONE should be ignored in the search*/
-char clifford_max_label(const ex & e, bool ignore_ONE = false);
+int clifford_max_label(const ex & e, bool ignore_ONE = false);
 
 /** Calculation of the norm in the Clifford algebra. */
 ex clifford_norm(const ex & e);