Fix header checks

Author: rhpvorderman

src/isal/igzip.py

@@ -170,12 +170,6 @@ def _read_eof(self):
         # Gzip files can be padded with zeroes and still have archives.
         # Consume all zero bytes and set the file position to the first
         # non-zero byte. See http://www.gzip.org/#faq8
-        # Also the isal_zlib.decompressobj does not consume the last two bytes
-        # when using ISAL_GZIP_NO_HDR.
-        for i in range(2):
-            c = self._fp.read(1)
-            if c == b"\x00":
-                break
         c = b"\x00"
         while c == b"\x00":
             c = self._fp.read(1)

src/isal/isal_zlib.pyx

@@ -577,7 +577,7 @@ cdef wbits_to_flag_and_hist_bits_inflate(int wbits,
         crc_flag[0] = ISAL_DEFLATE
     elif 72 <=wbits <= 79:
         hist_bits[0] = wbits - 64
-        crc_flag[0] = ISAL_GZIP_NO_HDR
+        crc_flag[0] = ISAL_GZIP_NO_HDR_VER
     else:
         raise ValueError("Invalid wbits value")