dgd-contributor commented on a change in pull request #33459:
URL: https://github.com/apache/spark/pull/33459#discussion_r677354506



##########
File path: 
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/NumberConverter.scala
##########
@@ -49,12 +49,14 @@ object NumberConverter {
    */
   private def encode(radix: Int, fromPos: Int, value: Array[Byte]): Long = {
     var v: Long = 0L
-    val bound = java.lang.Long.divideUnsigned(-1 - radix, radix) // Possible 
overflow once
+    // bound will always positive since radix >= 2
+    val bound = java.lang.Long.divideUnsigned(-1 - radix, radix)
     var i = fromPos
     while (i < value.length && value(i) >= 0) {
-      if (v >= bound) {

Review comment:
       1. Because v*radix >= v*2  (as radix >= 2), so if v is negative, which 
mean its bit presentation is start with 1, so if we multiply it by 2, it will 
cause overflow. 
   2. v >= bound is sufficient to v*radix + radix will cause overflow. But we 
need to check that v*radix + value(i) is overflow or not and v*radix + value(i) 
<= v*radix + radix




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