configure,curl: enable GSSAPI on Linux/MacOS/etc.

This will link libgssapi_krb5.so.2 which is in krb5-libs (ABI CL1 in
RHEL8, ABI CL2 in RHEL9).

Change-Id: I2dbaa64e70f4502c5a47c6c85123c94b9ad41277
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/170758
Tested-by: Jenkins
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

bin/check-elf-dynamic-objects

@@ -192,8 +192,15 @@ local file="$1"
         */libofficebean.so)
             allowlist="${allowlist} libjawt.so"
         ;;
+        */libcurl.so.4)
+            if [ "$WITH_GSSAPI" = TRUE ]; then
+                allowlist="${allowlist} ${kerberosallowlist}"
+            fi
+        ;;
         */libpostgresql-sdbc-impllo.so)
-            allowlist="${allowlist} ${kerberosallowlist}"
+            if [ "$WITH_GSSAPI" = TRUE ]; then
+                allowlist="${allowlist} ${kerberosallowlist}"
+            fi
         ;;
         */libmysqlclo.so)
             if [ "$WITH_GSSAPI" = TRUE ]; then

configure.ac

@@ -1060,6 +1060,7 @@ ios*) # iOS
     test_libcmis=no
     test_openldap=no
     test_webdav=no
+    with_gssapi=no
     if test -n "$LODE_HOME" ; then
         mac_sanitize_path
         AC_MSG_NOTICE([sanitized the PATH to $PATH])
@@ -1157,6 +1158,7 @@ linux-android*)
     test_openldap=no
     test_system_freetype=no
     test_webdav=no
+    with_gssapi=no
     disable_database_connectivity_dependencies
     enable_lotuswordpro=no
     enable_mpl_subset=yes
@@ -2798,7 +2800,7 @@ AC_ARG_WITH(locales,
 ,)
 
 # Kerberos and GSSAPI used only by PostgreSQL as of LibO 3.5
-# and also by Mariadb/Mysql since LibO 24.8
+# and also by Mariadb/Mysql and libcurl since LibO 24.8
 libo_FUZZ_ARG_WITH(krb5,
     AS_HELP_STRING([--with-krb5],
         [Enable MIT Kerberos 5 support in modules that support it.
@@ -10832,6 +10834,17 @@ dnl Check for system curl
 dnl ===================================================================
 libo_CHECK_SYSTEM_MODULE([curl],[CURL],[libcurl >= 7.68.0],enabled)
 
+if test "$enable_curl" = "yes" -a "$with_system_curl" != "yes" -a "$with_gssapi" != "no"; then
+    if test "$_os" != "WINNT"; then
+        WITH_GSSAPI=TRUE
+        save_LIBS=$LIBS
+        AC_SEARCH_LIBS(gss_init_sec_context, [gssapi_krb5 gss 'gssapi -lkrb5 -lcrypto'], [],
+            [AC_MSG_ERROR([could not find function 'gss_init_sec_context' required for GSSAPI])])
+        GSSAPI_LIBS=$LIBS
+        LIBS=$save_LIBS
+    fi
+fi
+
 dnl ===================================================================
 dnl Check for system boost
 dnl ===================================================================

external/curl/ExternalProject_curl.mk

@@ -43,7 +43,8 @@ $(call gb_ExternalProject_get_state_target,curl,build):
 			--without-libssh2 --without-nghttp2 \
 			--without-libssh --without-brotli \
 			--without-ngtcp2 --without-quiche \
-			--without-zstd --without-hyper --without-libgsasl --without-gssapi \
+			--without-zstd --without-hyper --without-libgsasl \
+			$(if $(WITH_GSSAPI),--with-gssapi,--without-gssapi) \
 			--disable-mqtt --disable-ares \
 			--disable-dict --disable-file --disable-gopher --disable-imap \
 			--disable-ldap --disable-ldaps --disable-manual --disable-pop3 \