HelenOS sources

GZIP_FLAG_FEXTRA  160 boot/generic/src/gzip.c 	if ((header.flags & GZIP_FLAG_FEXTRA) != 0) {
GZIP_FLAG_FEXTRA  113 uspace/lib/compress/gzip.c 	if ((header.flags & GZIP_FLAG_FEXTRA) != 0) {
HelenOS homepage, sources at GitHub