We are obliged to define HAVE_UNISTD_H in "config.h"; to avoid the

hideous problem on FreeBSD 3.[23] (and perhaps other BSDs) if
HAVE_UNISTD_H is defined before "zlib.h" is included, turn "file_seek()"
into a subroutine defined in a file that *undefines* HAVE_UNISTD_H
before including "zlib.h", so that the *only* call to "gzseek()" is made
from a file that does not have HAVE_UNISTD_H defined when it includes
"zlib.h".

Move "file_error()" to that file while you're at it, so it holds all the
wrappers that hide the presence or absence of zlib from routines to read
capture files.

Turn "file.h", which declared those wrapper functions as well as wrapper
macros, into "file_wrapper.h" - it belongs with the "file_wrapper.c"
file that defines the wrapper functions, not with "file.c" which handles
higher-layer file access functions.

Remove the comment in "configure.in" that explained why defining
HAVE_UNISTD_H was a bad idea, as we're not obliged to define it and work
around the problem.  (The comment in "file_wrapper.c" explains the
workaround.)


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@1463 f5534014-38df-0310-8fa8-9805f1628bb7

1 files changed, 1 insertions, 42 deletions

diff --git a/wiretap/configure.in b/wiretap/configure.in
index dbd1c9ea7e..884f901e14 100644
--- a/wiretap/configure.in
+++ b/wiretap/configure.in
@@ -1,4 +1,4 @@
-# $Id: configure.in,v 1.19 2000/01/10 17:33:17 gram Exp $
+# $Id: configure.in,v 1.20 2000/01/13 07:09:15 guy Exp $
 dnl
 dnl Process this file with autoconf 2.13 or later to produce a
 dnl configure script; 2.12 doesn't generate a "configure" script that
@@ -45,47 +45,6 @@ if test "x$GLIB_CFLAGS" = x ; then
 fi
 
 dnl Checks for header files
-dnl WARNING: do *NOT* check for "unistd.h" unless you work around the
-dnl following problem:
-dnl
-dnl At least on FreeBSD 3.2, "/usr/include/zlib.h" includes
-dnl "/usr/include/zconf.h", which, if HAVE_UNISTD_H is defined,
-dnl #defines "z_off_t" to be "off_t", and if HAVE_UNISTD_H is
-dnl not defines, #defines "z_off_t" to be "long" if it's not
-dnl already #defined.
-dnl
-dnl In 4.4-Lite-derived systems such as FreeBSD, "off_t" is
-dnl "long long int", not "long int", so the definition of "z_off_t" -
-dnl and therefore the types of the arguments to routines such as
-dnl "gzseek()", as declared, with prototypes, in "zlib.h" - depends
-dnl on whether HAVE_UNISTD_H is defined prior to including "zlib.h"!
-dnl
-dnl It's not defined in the FreeBSD 3.2 "zlib", so if we include "zlib.h"
-dnl after defining HAVE_UNISTD_H, we get a misdeclaration of "gzseek()",
-dnl and, if we're building with "zlib" support, anything that seeks
-dnl on a file may not work.
-dnl
-dnl Other BSDs may have the same problem, if they haven't done something
-dnl such as defining HAVE_UNISTD_H in "zconf.h".
-dnl
-dnl If "config.h" defines HAVE_UNISTD_H - which it will, on all systems
-dnl that have it, if we test for it here, and all 4.4-Lite-derived
-dnl BSDs have it - then, given that "zlib.h" is included by "file.h",
-dnl that means that unless we include "zlib.h" before we include
-dnl "config.h", we get a misdeclaration of "gzseek()".
-dnl
-dnl Unfortunately, it's "config.h" that tells us whether we have "zlib"
-dnl in the first place, so we don't know whether to include "zlib.h"
-dnl until we include "config.h"....
-dnl
-dnl Fortunately, we don't use "unistd.h", so we don't need to check
-dnl for it.
-dnl
-dnl If we ever *do* end up requiring HAVE_UNISTD_H, a fix might be to
-dnl turn "file_seek()" into a subroutine, at least if HAVE_ZLIB is
-dnl defined, have it take an "off_t" as its second argument, and
-dnl put it into a file that doesn't require HAVE_UNISTD_H.
-dnl
 AC_HEADER_STDC
 AC_CHECK_HEADERS(sys/time.h netinet/in.h unistd.h)