--- old/test/testlibrary/com/oracle/java/testlibrary/Asserts.java	2014-03-21 17:36:50.449946574 +0400
+++ new/test/testlibrary/com/oracle/java/testlibrary/Asserts.java	2014-03-21 17:36:50.181946585 +0400
@@ -378,6 +378,64 @@
         }
     }
 
+    /**
+     * Asserts that two strings are equal.
+     *
+     * If strings are not equals, then exception message
+     * will contain {@code msg} followed by list of mismatched lines.
+     *
+     * @param str1 First string to compare.
+     * @param str2 Second string to compare.
+     * @param msg A description of the assumption.
+     * @throws RuntimeException if strings are not equal.
+     */
+    public static void assertStringsEqual(String str1, String str2,
+                                          String msg) {
+        String lineSeparator = System.getProperty("line.separator");
+        String str1Lines[] = str1.split(lineSeparator);
+        String str2Lines[] = str2.split(lineSeparator);
+
+        int minLength = Math.min(str1Lines.length, str2Lines.length);
+        String longestStringLines[] = ((str1Lines.length == minLength) ?
+                                       str2Lines : str1Lines);
+
+        boolean stringsAreDifferent = false;
+
+        StringBuilder messageBuilder = new StringBuilder(msg);
+
+        messageBuilder.append("\n");
+
+        for (int line = 0; line < minLength; line++) {
+            if (!str1Lines[line].equals(str2Lines[line])) {
+                messageBuilder.append(String.
+                                      format("[line %d] '%s' differs " +
+                                             "from '%s'\n",
+                                             line,
+                                             str1Lines[line],
+                                             str2Lines[line]));
+                stringsAreDifferent = true;
+            }
+        }
+
+        if (minLength < longestStringLines.length) {
+            String stringName = ((longestStringLines == str1Lines) ?
+                                 "first" : "second");
+            messageBuilder.append(String.format("Only %s string contains " +
+                                                "following lines:\n",
+                                                stringName));
+            stringsAreDifferent = true;
+            for(int line = minLength; line < longestStringLines.length; line++) {
+                messageBuilder.append(String.
+                                      format("[line %d] '%s'", line,
+                                             longestStringLines[line]));
+            }
+        }
+
+        if (stringsAreDifferent) {
+            error(messageBuilder.toString());
+        }
+    }
+
     private static <T extends Comparable<T>> int compare(T lhs, T rhs, String msg) {
         assertNotNull(lhs, msg);
         assertNotNull(rhs, msg);