System.RegGetValue{,s} does not handle DWORD entries correctly.

src/modules/system/nt.c:push_regvalue() uses the wrong shifts for bytes other than the LSB:

    case REG_DWORD_LITTLE_ENDIAN:
      push_int(EXTRACT_UCHAR(buffer)+
               (EXTRACT_UCHAR(buffer+1)<<1)+
               (EXTRACT_UCHAR(buffer+2)<<2)+
               (EXTRACT_UCHAR(buffer+3)<<3));
      break;
      
    case REG_DWORD_BIG_ENDIAN:
      push_int(EXTRACT_UCHAR(buffer+3)+
               (EXTRACT_UCHAR(buffer+2)<<1)+
               (EXTRACT_UCHAR(buffer+1)<<2)+
               (EXTRACT_UCHAR(buffer)<<3));
      break;

Fortunately it seems like the most common DWORD entries in the registry are <= 255.

This bug has been there since the original implementation of System.RegGetValues() et al in commit 53bdc644 (src/modules/system/nt.c:1.18) in Pike 7.1.5.

Note that the bug is also present in Pike 7.0.318 and later due to a backport in commit 9481e19e (src/modules/system/nt.c:1.19).

The bug should be fixed in all relevant versions of Pike.