This is simple mistake. *** xemacs-21.5.orig/src/file-coding.h Sun May 5 20:31:25 2002 --- xemacs-21.5/src/file-coding.h Wed Jun 5 17:16:47 2002 *************** *** 756,762 **** DET_QUITE_IMPROBABLE = -2, /* An erroneous sequence was seen. */ DET_NEARLY_IMPOSSIBLE = -3, ! DET_LOWEST = 3, }; extern int coding_detector_count; --- 756,762 ---- DET_QUITE_IMPROBABLE = -2, /* An erroneous sequence was seen. */ DET_NEARLY_IMPOSSIBLE = -3, ! DET_LOWEST = -3, }; extern int coding_detector_count; Now detection method is wonderful. :-)