1 files changed, 11 insertions, 1 deletions

diff --git a/zconf.h.cmakein b/zconf.h.cmakein
index cf9cc24..18dd770 100644
--- a/zconf.h.cmakein
+++ b/zconf.h.cmakein
@@ -317,7 +317,7 @@
 #  endif
 #endif
 
-#ifdef HAVE_VISIBILITY_PRAGMA
+#ifndef NO_VIZ
 #  define ZEXTERN __attribute__((visibility ("default"))) extern
 #endif
 
@@ -370,6 +370,16 @@ typedef uLong FAR uLongf;
 #  include <sys/types.h>    /* for off_t */
 #endif
 
+/* a little trick to accommodate both "#define _LARGEFILE64_SOURCE" and
+ * "#define _LARGEFILE64_SOURCE 1" as requesting 64-bit operations, (even
+ * though the former does not conform to the LFS document), but considering
+ * both "#undef _LARGEFILE64_SOURCE" and "#define _LARGEFILE64_SOURCE 0" as
+ * equivalently requesting no 64-bit operations
+ */
+#if -_LARGEFILE64_SOURCE - -1 == 1
+#  undef _LARGEFILE64_SOURCE
+#endif
+
 #if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
 #  include <unistd.h>       /* for SEEK_* and off_t */
 #  ifdef VMS