8 files changed, 75 insertions, 25 deletions

diff --git a/src/gns/gnunet-bcd.c b/src/gns/gnunet-bcd.c
index d6de86fa0..6ceff4a9a 100644
--- a/src/gns/gnunet-bcd.c
+++ b/src/gns/gnunet-bcd.c
@@ -27,6 +27,7 @@
 #include "platform.h"
 #include <microhttpd.h>
 #include "gnunet_util_lib.h"
+#include "gnunet_mhd_compat.h"
 
 /**
  * Error page to display if submitted GNS key is invalid.
@@ -91,7 +92,7 @@ struct Entry
 /**
  * Main request handler.
  */
-static int
+static MHD_RESULT
 access_handler_callback (void *cls,
                          struct MHD_Connection *connection,
                          const char *url,
@@ -153,7 +154,7 @@ access_handler_callback (void *cls,
     struct stat st;
     struct MHD_Response *response;
     int fd;
-    int ret;
+    MHD_RESULT ret;
 
     const char *gpg_fp = MHD_lookup_connection_value (connection,
                                                       MHD_GET_ARGUMENT_KIND,
diff --git a/src/gns/gnunet-gns-proxy.c b/src/gns/gnunet-gns-proxy.c
index 5b8348d43..c0572fe40 100644
--- a/src/gns/gnunet-gns-proxy.c
+++ b/src/gns/gnunet-gns-proxy.c
@@ -43,7 +43,7 @@
 #include "gnunet_gns_service.h"
 #include "gnunet_identity_service.h"
 #include "gns.h"
-
+#include "gnunet_mhd_compat.h"
 
 /**
  * Default Socks5 listen port.
@@ -1827,7 +1827,7 @@ con_val_iter (void *cls,
  *         #MHD_NO if the socket must be closed due to a serious
  *         error while handling the request
  */
-static int
+static MHD_RESULT
 create_response (void *cls,
                  struct MHD_Connection *con,
                  const char *url,
diff --git a/src/include/Makefile.am b/src/include/Makefile.am
index 5c57b5be2..d2c254ae6 100644
--- a/src/include/Makefile.am
+++ b/src/include/Makefile.am
@@ -62,6 +62,7 @@ gnunetinclude_HEADERS = \
   gnunet_json_lib.h \
   gnunet_load_lib.h \
   gnunet_cadet_service.h \
+  gnunet_mhd_compat.h \
   gnunet_microphone_lib.h \
   gnunet_mst_lib.h \
   gnunet_mq_lib.h \
diff --git a/src/include/gnunet_mhd_compat.h b/src/include/gnunet_mhd_compat.h
new file mode 100644
index 000000000..0cfcc6445
--- /dev/null
+++ b/src/include/gnunet_mhd_compat.h
@@ -0,0 +1,43 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2020 GNUnet e.V.
+
+     GNUnet is free software: you can redistribute it and/or modify it
+     under the terms of the GNU Affero General Public License as published
+     by the Free Software Foundation, either version 3 of the License,
+     or (at your option) any later version.
+
+     GNUnet is distributed in the hope that it will be useful, but
+     WITHOUT ANY WARRANTY; without even the implied warranty of
+     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+     Affero General Public License for more details.
+
+     You should have received a copy of the GNU Affero General Public License
+     along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+     SPDX-License-Identifier: AGPL3.0-or-later
+ */
+
+/**
+ * @author Christian Grothoff
+ *
+ * @file
+ * MHD compatibility definitions for warning-less compile of
+ * our code against MHD before and after #MHD_VERSION 0x00097002.
+ */
+#include <microhttpd.h>
+
+#if MHD_VERSION >= 0x00097002
+/**
+ * Data type to use for functions return an "MHD result".
+ */
+#define MHD_RESULT enum MHD_Result
+
+#else
+
+/**
+ * Data type to use for functions return an "MHD result".
+ */
+#define MHD_RESULT int
+
+#endif
diff --git a/src/namestore/gnunet-namestore-fcfsd.c b/src/namestore/gnunet-namestore-fcfsd.c
index fa0f835d1..67fc5bdf4 100644
--- a/src/namestore/gnunet-namestore-fcfsd.c
+++ b/src/namestore/gnunet-namestore-fcfsd.c
@@ -36,6 +36,7 @@
 #include "gnunet_identity_service.h"
 #include "gnunet_gnsrecord_lib.h"
 #include "gnunet_namestore_service.h"
+#include "gnunet_mhd_compat.h"
 
 /**
  * Invalid method page.
@@ -507,10 +508,10 @@ fill_s_reply (const char *info,
  *              specified offset
  * @param off offset of data in the overall value
  * @param size number of bytes in data available
- * @return MHD_YES to continue iterating,
- *         MHD_NO to abort the iteration
+ * @return #MHD_YES to continue iterating,
+ *         #MHD_NO to abort the iteration
  */
-static int
+static MHD_RESULT
 post_iterator (void *cls,
                enum MHD_ValueKind kind,
                const char *key,
@@ -754,7 +755,7 @@ lookup_it_finished (void *cls)
  *         #MHD_NO if the socket must be closed due to a serious
  *         error while handling the request
  */
-static int
+static MHD_RESULT
 create_response (void *cls,
                  struct MHD_Connection *connection,
                  const char *url,
@@ -767,7 +768,7 @@ create_response (void *cls,
   struct MHD_Response *response;
   struct Request *request;
   struct GNUNET_CRYPTO_EcdsaPublicKey pub;
-  int ret;
+  MHD_RESULT ret;
 
   (void) cls;
   (void) version;
diff --git a/src/pq/pq_result_helper.c b/src/pq/pq_result_helper.c
index 1fb1e71c0..dc64597f8 100644
--- a/src/pq/pq_result_helper.c
+++ b/src/pq/pq_result_helper.c
@@ -345,7 +345,7 @@ extract_rsa_signature (void *cls,
 {
   struct GNUNET_CRYPTO_RsaSignature **sig = dst;
   size_t len;
-  const char *res;
+  const void *res;
   int fnum;
 
   (void) cls;
diff --git a/src/rest/gnunet-rest-server.c b/src/rest/gnunet-rest-server.c
index 02a2c6daf..30eade623 100644
--- a/src/rest/gnunet-rest-server.c
+++ b/src/rest/gnunet-rest-server.c
@@ -27,7 +27,7 @@
 #include <microhttpd.h>
 #include "gnunet_util_lib.h"
 #include "gnunet_rest_plugin.h"
-
+#include "gnunet_mhd_compat.h"
 
 /**
  * Default Socks5 listen port.
@@ -302,7 +302,7 @@ url_iterator (void *cls,
 }
 
 
-static int
+static MHD_RESULT
 post_data_iter (void *cls,
                 enum MHD_ValueKind kind,
                 const char *key,
@@ -359,11 +359,11 @@ post_data_iter (void *cls,
  *        @a upload_data provided; the method must update this
  *        value to the number of bytes NOT processed;
  * @param con_cls pointer to location where we store the 'struct Request'
- * @return MHD_YES if the connection was handled successfully,
- *         MHD_NO if the socket must be closed due to a serious
+ * @return #MHD_YES if the connection was handled successfully,
+ *         #MHD_NO if the socket must be closed due to a serious
  *         error while handling the request
  */
-static int
+static MHD_RESULT
 create_response (void *cls,
                  struct MHD_Connection *con,
                  const char *url,
@@ -430,7 +430,7 @@ create_response (void *cls,
                                rest_conndata_handle);
     con_handle->pp = MHD_create_post_processor (con,
                                                 65536,
-                                                post_data_iter,
+                                                &post_data_iter,
                                                 rest_conndata_handle);
     if (*upload_data_size)
     {
@@ -509,9 +509,13 @@ create_response (void *cls,
                              allow_headers);
   }
   run_mhd_now ();
-  int ret = MHD_queue_response (con, con_handle->status, con_handle->response);
-  cleanup_handle (con_handle);
-  return ret;
+  {
+    MHD_RESULT ret = MHD_queue_response (con,
+                                         con_handle->status,
+                                         con_handle->response);
+    cleanup_handle (con_handle);
+    return ret;
+  }
 }
 
 
diff --git a/src/transport/plugin_transport_http_server.c b/src/transport/plugin_transport_http_server.c
index 20bdb6273..eef83b29d 100644
--- a/src/transport/plugin_transport_http_server.c
+++ b/src/transport/plugin_transport_http_server.c
@@ -33,7 +33,7 @@
 #include "plugin_transport_http_common.h"
 #include <microhttpd.h>
 #include <regex.h>
-
+#include "gnunet_mhd_compat.h"
 
 #if BUILD_HTTPS
 #define PLUGIN_NAME "https_server"
@@ -1741,9 +1741,9 @@ add_cors_headers (struct MHD_Response *response)
  * @param upload_data upload data
  * @param upload_data_size size of @a upload_data
  * @param httpSessionCache the session cache to remember the connection
- * @return MHD_YES if connection is accepted, MHD_NO on reject
+ * @return #MHD_YES if connection is accepted, #MHD_NO on reject
  */
-static int
+static MHD_RESULT
 server_access_cb (void *cls,
                   struct MHD_Connection *mhd_connection,
                   const char *url,
@@ -1757,7 +1757,7 @@ server_access_cb (void *cls,
   struct ServerRequest *sc = *httpSessionCache;
   struct GNUNET_ATS_Session *s;
   struct MHD_Response *response;
-  int res = MHD_YES;
+  MHD_RESULT res = MHD_YES;
 
   LOG (GNUNET_ERROR_TYPE_DEBUG,
        _ (
@@ -2025,9 +2025,9 @@ server_connection_cb (void *cls,
  * @param cls plugin as closure
  * @param addr address of incoming connection
  * @param addr_len number of bytes in @a addr
- * @return MHD_YES if connection is accepted, MHD_NO if connection is rejected
+ * @return #MHD_YES if connection is accepted, #MHD_NO if connection is rejected
  */
-static int
+static MHD_RESULT
 server_accept_cb (void *cls,
                   const struct sockaddr *addr,
                   socklen_t addr_len)