--- old/src/java.base/share/classes/java/lang/String.java	2017-03-22 15:53:01.000000000 +0300
+++ new/src/java.base/share/classes/java/lang/String.java	2017-03-22 15:53:01.000000000 +0300
@@ -1121,6 +1121,8 @@
                 }
             }
         } else {
+            // Redundant: n == length() (see earlier check)
+            checkOffset(n, val.length >> 1);
             for (int i = 0; i < n; i++) {
                 if (StringUTF16.getChar(val, i) != cs.charAt(i)) {
                     return false;
@@ -1834,7 +1836,19 @@
         int i = min + fromIndex;
         int strLastIndex = tgtCount - 1;
 
-        char strLastChar = (char)(tgt[strLastIndex] & 0xff);
+        char strLastChar = (char) (tgt[strLastIndex] & 0xff);
+
+        // Redundant:
+        //   i == min + fromIndex
+        //   fromIndex <= rightIndex (earlier check) ==>
+        //     i <= min + rightIndex == (tgtCount - 1) + (srcCount - tgtCount) == srcCount - 1 ==>
+        //     i <= srcCount - 1
+        //
+        // And (srcCount < src.length >> 1) is covered by:
+        //     ASB.lastIndexOf(String str, int fromIndex) {
+        //         checkIndex(count, value.length >> coder);
+        checkIndex(i, src.length >> 1);
+
         startSearchForLastChar:
         while (true) {
             while (i >= min && StringUTF16.getChar(src, i) != strLastChar) {