+dnl Check for the presence of ZLIB libraries and headers
+dnl **********************************************************************
+
+dnl Check for & handle argument to --with-zlib.
+
+clean_CPPFLAGS=$CPPFLAGS
+clean_LDFLAGS=$LDFLAGS
+clean_LIBS=$LIBS
+ZLIB_LIBS=""
+AC_ARG_WITH(zlib,
+AC_HELP_STRING([--with-zlib=PATH],[search for zlib in PATH])
+AC_HELP_STRING([--without-zlib],[disable use of zlib]),
+ [OPT_ZLIB="$withval"])
+
+if test "$OPT_ZLIB" = "no" ; then
+ AC_MSG_WARN([zlib disabled])
+else
+ if test "$OPT_ZLIB" = "yes" ; then
+ OPT_ZLIB=""
+ fi
+
+ if test -z "$OPT_ZLIB" ; then
+ CURL_CHECK_PKGCONFIG(zlib)
+
+ if test "$PKGCONFIG" != "no" ; then
+ LIBS="`$PKGCONFIG --libs-only-l zlib` $LIBS"
+ LDFLAGS="$LDFLAGS `$PKGCONFIG --libs-only-L zlib`"
+ CPPFLAGS="$CPPFLAGS `$PKGCONFIG --cflags-only-I zlib`"
+ OPT_ZLIB=""
+ HAVE_LIBZ="1"
+ fi
+
+ if test -z "$HAVE_LIBZ"; then
+
+ dnl Check for the lib without setting any new path, since many
+ dnl people have it in the default path
+
+ AC_CHECK_LIB(z, inflateEnd,
+ dnl libz found, set the variable
+ [HAVE_LIBZ="1"
+ LIBS="-lz $LIBS"],
+ dnl if no lib found, try /usr/local
+ [OPT_ZLIB="/usr/local"])
+ fi
+ fi
+
+ dnl Add a nonempty path to the compiler flags
+ if test -n "$OPT_ZLIB"; then
+ CPPFLAGS="$CPPFLAGS -I$OPT_ZLIB/include"
+ LDFLAGS="$LDFLAGS -L$OPT_ZLIB/lib$libsuff"
+ fi
+
+ AC_CHECK_HEADER(zlib.h,
+ [
+ dnl zlib.h was found
+ HAVE_ZLIB_H="1"
+ dnl if the lib wasn't found already, try again with the new paths
+ if test "$HAVE_LIBZ" != "1"; then
+ AC_CHECK_LIB(z, gzread,
+ [
+ dnl the lib was found!
+ HAVE_LIBZ="1"
+ LIBS="-lz $LIBS"
+ ],
+ [ CPPFLAGS=$clean_CPPFLAGS
+ LDFLAGS=$clean_LDFLAGS])
+ fi
+ ],
+ [
+ dnl zlib.h was not found, restore the flags
+ CPPFLAGS=$clean_CPPFLAGS
+ LDFLAGS=$clean_LDFLAGS]
+ )
+
+ if test "$HAVE_LIBZ" = "1" && test "$HAVE_ZLIB_H" != "1"
+ then
+ AC_MSG_WARN([configure found only the libz lib, not the header file!])
+ HAVE_LIBZ=""
+ CPPFLAGS=$clean_CPPFLAGS
+ LDFLAGS=$clean_LDFLAGS
+ LIBS=$clean_LIBS
+ elif test "$HAVE_LIBZ" != "1" && test "$HAVE_ZLIB_H" = "1"
+ then
+ AC_MSG_WARN([configure found only the libz header file, not the lib!])
+ CPPFLAGS=$clean_CPPFLAGS
+ LDFLAGS=$clean_LDFLAGS
+ LIBS=$clean_LIBS
+ elif test "$HAVE_LIBZ" = "1" && test "$HAVE_ZLIB_H" = "1"
+ then
+ dnl both header and lib were found!
+ AC_SUBST(HAVE_LIBZ)
+ AC_DEFINE(HAVE_ZLIB_H, 1, [if you have the zlib.h header file])
+ AC_DEFINE(HAVE_LIBZ, 1, [if zlib is available])
+
+ ZLIB_LIBS="-lz"
+ LIBS="-lz $clean_LIBS"
+
+ dnl replace 'HAVE_LIBZ' in the automake makefile.ams
+ AMFIXLIB="1"
+ AC_MSG_NOTICE([found both libz and libz.h header])
+ curl_zlib_msg="enabled"
+ fi
+fi
+
+dnl set variable for use in automakefile(s)
+AM_CONDITIONAL(HAVE_LIBZ, test x"$AMFIXLIB" = x1)
+AC_SUBST(ZLIB_LIBS)
+
+dnl **********************************************************************
+dnl Check for the presence of BROTLI decoder libraries and headers
+dnl **********************************************************************
+
+dnl Brotli project home page: https://github.com/google/brotli
+
+dnl Default to compiler & linker defaults for BROTLI files & libraries.
+OPT_BROTLI=off
+AC_ARG_WITH(brotli,dnl
+AC_HELP_STRING([--with-brotli=PATH],[Where to look for brotli, PATH points to the BROTLI installation; when possible, set the PKG_CONFIG_PATH environment variable instead of using this option])
+AC_HELP_STRING([--without-brotli], [disable BROTLI]),
+ OPT_BROTLI=$withval)
+
+if test X"$OPT_BROTLI" != Xno; then
+ dnl backup the pre-brotli variables
+ CLEANLDFLAGS="$LDFLAGS"
+ CLEANCPPFLAGS="$CPPFLAGS"
+ CLEANLIBS="$LIBS"
+
+ case "$OPT_BROTLI" in