Index: src/main/java/java/io/InputStreamReader.java =================================================================== --- src/main/java/java/io/InputStreamReader.java (revision 548000) +++ src/main/java/java/io/InputStreamReader.java (working copy) @@ -100,7 +100,8 @@ CodingErrorAction.REPLACE).onUnmappableCharacter( CodingErrorAction.REPLACE); } catch (IllegalArgumentException e) { - throw new UnsupportedEncodingException(); + throw (UnsupportedEncodingException) + new UnsupportedEncodingException().initCause(e); } bytes.limit(0); }