Merge pull request scala/scala#10592 from guizmaii/fix_212_javaBigDecimal2bigDecimal

[backport] Fixes implicit `javaBigDecimal2bigDecimal` to return `null`, when a `null` is used by the implicit

Author: lrytz

library/src/scala/math/BigDecimal.scala

@@ -344,7 +344,7 @@ object BigDecimal {
   implicit def double2bigDecimal(d: Double): BigDecimal = decimal(d)
 
   /** Implicit conversion from `java.math.BigDecimal` to `scala.BigDecimal`. */
-  implicit def javaBigDecimal2bigDecimal(x: BigDec): BigDecimal = apply(x)
+  implicit def javaBigDecimal2bigDecimal(x: BigDec): BigDecimal = if (x == null) null else apply(x)
 }
 
 /**

library/src/scala/math/BigInt.scala

@@ -105,7 +105,7 @@ object BigInt {
 
   /** Implicit conversion from `java.math.BigInteger` to `scala.BigInt`.
    */
-  implicit def javaBigInteger2bigInt(x: BigInteger): BigInt = apply(x)
+  implicit def javaBigInteger2bigInt(x: BigInteger): BigInt = if (x eq null) null else apply(x)
 }
 
 /**