Index: ext/filter/filter_private.h
===================================================================
RCS file: /repository/php-src/ext/filter/filter_private.h,v
retrieving revision 1.12.2.6
diff -u -p -d -r1.12.2.6 filter_private.h
--- ext/filter/filter_private.h	5 Dec 2006 01:24:18 -0000	1.12.2.6
+++ ext/filter/filter_private.h	18 Dec 2006 13:24:37 -0000
@@ -94,18 +94,20 @@
 		len--; \
 	} \
 	start = p; \
-	end = p + len - 1; \
-	if (*end == ' ' || *end == '\t' || *end == '\r' || *end == '\v') { \
-		unsigned int i; \
-		for (i = len - 1; i >= 0; i--) { \
-			if (!(p[i] == ' ' || p[i] == '\t' || p[i] == '\r' || p[i] == '\v')) { \
-				break; \
+	if (len) { \
+		end = p + len - 1; \
+		if (*end == ' ' || *end == '\t' || *end == '\r' || *end == '\v') { \
+			unsigned int i; \
+			for (i = len - 1; i >= 0; i--) { \
+				if (!(p[i] == ' ' || p[i] == '\t' || p[i] == '\r' || p[i] == '\v')) { \
+					break; \
+				} \
 			} \
+			i++; \
+			p[i] = '\0'; \
+			end = p + i - 1; \
+			len = (int) (end - p) + 1; \
 		} \
-		i++; \
-		p[i] = '\0'; \
-		end = p + i - 1; \
-		len = (int) (end - p) + 1; \
 	} \
 }