6857707: Add missing test case for CR 6855164 from its bug description.

Summary: Add missing test case for CR 6855164 from its bug description.
Reviewed-by: never

test/compiler/6855164/Test.java

+/*
+ * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test
+ * @bug 6855164
+ * @summary SIGSEGV during compilation of method involving loop over CharSequence
+ * @run main/othervm -Xbatch Test
+ */
+
+public class Test{
+    public static void main(String[] args) throws Exception {
+        StringBuffer builder = new StringBuffer();
+
+        for(int i = 0; i < 100; i++)
+            builder.append("I am the very model of a modern major general\n");
+
+        for(int j = 0; j < builder.length(); j++){
+            previousSpaceIndex(builder, j);
+        }
+    }
+
+    private static final int previousSpaceIndex(CharSequence sb, int seek) {
+        seek--;
+        while (seek > 0) {
+            if (sb.charAt(seek) == ' ') {
+                while (seek > 0 && sb.charAt(seek - 1) == ' ')
+                    seek--;
+                return seek;
+            }
+            seek--;
+        }
+        return 0;
+    }
+}