Disable zib header tests

Author: pmqs

t/005defhdr.t

@@ -19,7 +19,7 @@ BEGIN {
     $extra = 1
         if eval { require Test::NoWarnings ;  import Test::NoWarnings; 1 };
 
-    plan tests => 595 + $extra ;
+    plan tests => 114 + $extra ;
 
     use_ok('Compress::Raw::Zlib') ;
 
@@ -123,6 +123,7 @@ EOM
 
 }
 
+if (0) # disable these tests: IO::Compress::Deflate doesn't create the zlib header itself so no need to test
 {
     title "Check user-defined header settings match zlib" ;
 
@@ -168,8 +169,9 @@ EOM
 
         my $hdr1 = ReadHeaderInfoZlib($string, %$opts);
 
-        # zlib-ng with Level 1 sets the CINFO value to 5 for some reason. All others use expected value of 7
-        my $cinfoValue =  Compress::Raw::Zlib::is_zlibng() && defined $opts->{'-Level'} && $opts->{'-Level'} == 1 ? 5 : 7;
+        # zlib-ng <= 2.0.6 with Level 1 sets the CINFO value to 5 . All other zlib & zlib-ng use expected value of 7
+        # Note that zlib-ng 2.0.x uses a 16-bit encoding for ZLIBNG_VERNUM
+        my $cinfoValue =  Compress::Raw::Zlib::is_zlibng() && Compress::Raw::Zlib::ZLIBNG_VERNUM() <= 0x2060 && defined $opts->{'-Level'} && $opts->{'-Level'} == 1 ? 5 : 7;
         is $hdr->{CM},     8, "  CM is 8";
         is $hdr->{CINFO},  $cinfoValue, "  CINFO is $cinfoValue";
         is $hdr->{FDICT},  0, "  FDICT is 0";