configure: fixed detection of 'getsockname' on some systems (W32 x32),

do not use 'getsockname()' if it is not detected by configure.

configure.ac

@@ -789,12 +789,25 @@ AC_CHECK_MEMBERS([struct sockaddr_in.sin_len, struct sockaddr_in6.sin6_len,
 #endif
    ])
 
-AC_CHECK_DECLS([getsockname],
+MHD_CHECK_FUNC([getsockname],
+  [[
+#ifdef HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#ifdef HAVE_WINSOCK2_H
+#include <winsock2.h>
+#endif
+  ]],
   [
-   AC_CHECK_FUNCS([getsockname],
-     [
-      AC_CACHE_CHECK([[whether getsockname() is usable]], [[mhc_cv_getsockname_usable]],
-        [
+    struct sockaddr_storage ss;
+    (void)getsockname(socket(0,0,0),(struct sockaddr *)&ss,(void*)0);
+  ],
+  [
+    AC_CACHE_CHECK([[whether getsockname() is usable]], [[mhc_cv_getsockname_usable]],
+      [
          AC_RUN_IFELSE(
            [
             AC_LANG_SOURCE(
@@ -888,22 +901,9 @@ int main(void)
          )
         ]
       )
-      AS_VAR_IF([[mhc_cv_getsockname_usable]], [["no"]], [:],
+    AS_VAR_IF([[mhc_cv_getsockname_usable]], [["no"]], [:],
         [AC_DEFINE([[MHD_USE_GETSOCKNAME]], [[1]], [Define if you have usable `getsockname' function.])])
-     ]
-   )
-  ], [],
-  [[
-#ifdef HAVE_SYS_TYPES_H
-#include <sys/types.h>
-#endif
-#ifdef HAVE_SYS_SOCKET_H
-#include <sys/socket.h>
-#endif
-#ifdef HAVE_WINSOCK2_H
-#include <winsock2.h>
-#endif
-  ]]
+  ]
 )
 
 # Check for inter-thread signaling type

m4/mhd_check_func.m4

@@ -0,0 +1,80 @@
+# SYNOPSIS
+#
+#   MHD_CHECK_FUNC([FUNCTION_NAME],
+#                  [INCLUDES=AC_INCLUDES_DEFAULT], [CHECK_CODE],
+#                  [ACTION-IF-AVAILABLE], [ACTION-IF-NOT-AVAILABLE],
+#                  [ADDITIONAL_LIBS])
+#
+# DESCRIPTION
+#
+#   This macro checks for presence of specific function by including
+#   specified headers and compiling and linking CHECK_CODE.
+#   This check both declaration and presence in library.
+#   Unlike AC_CHECK_FUNCS macro, this macro do not produce false
+#   negative result if function is declared with specific calling
+#   conventions like __stdcall' or attribute like
+#   __attribute__((__dllimport__)) and linker failed to build test
+#   program if library contains function with calling conventions
+#   different from declared. 
+#   By using definition from provided headers, this macro ensures that
+#   correct calling convention is used for detection.
+#
+#   Example usage:
+#
+#     MHD_CHECK_FUNC([memmem],
+#                    [[#include <string.h>]],
+#                    [const void *ptr = memmem("aa", 2, "a", 1); (void)ptr;],
+#                    [var_use_memmem='yes'], [var_use_memmem='no'])
+#
+#   Defined cache variable used in check so if any test will not work
+#   correctly on some platform, user may simply fix it by giving cache
+#   variable in configure parameters, for example:
+#
+#     ./configure mhd_cv_func_memmem_have=no
+#
+#   This simplify building from source on exotic platforms as patching
+#   of configure.ac is not required to change results of tests.
+#
+# LICENSE
+#
+#   Copyright (c) 2019 Karlson2k (Evgeny Grin) <[email protected]>
+#
+#   Copying and distribution of this file, with or without modification, are
+#   permitted in any medium without royalty provided the copyright notice
+#   and this notice are preserved. This file is offered as-is, without any
+#   warranty.
+
+#serial 1
+
+AC_DEFUN([MHD_CHECK_FUNC],[dnl
+  AC_PREREQ([2.64])dnl for AS_VAR_IF, m4_ifblank, m4_ifnblank
+  m4_ifblank(m4_translit([$1],[()],[  ]), [m4_fatal([First macro argument must not be empty])])dnl
+  m4_ifblank([$3], [m4_fatal([Third macro argument must not be empty])])dnl
+  m4_bmatch(m4_normalize([$1]), [\s],dnl
+            [m4_fatal([First macro argument must not contain whitespaces])])dnl
+  m4_if(m4_index([$3], m4_normalize(m4_translit([$1],[()],[  ]))), [-1], dnl
+        [m4_fatal([CHECK_CODE parameter (third macro argument) do not contain ']m4_normalize([$1])[' token])])dnl
+  AS_VAR_PUSHDEF([cv_Var], [mhd_cv_func_]m4_bpatsubst(m4_normalize(m4_translit([$1],[()],[  ])),[[^a-zA-Z0-9]],[_]))dnl
+  dnl
+  AC_CACHE_CHECK([for function $1], [cv_Var],
+    [dnl
+      m4_ifnblank([$6],[dnl
+        mhd_check_func_SAVE_LIBS="$LIBS"
+        LIBS="$LIBS m4_normalize([$6])"
+      ])dnl
+      AC_LINK_IFELSE(
+        [AC_LANG_PROGRAM([m4_default_nblank([$2],[AC_INCLUDES_DEFAULT])], [$3]) ],
+        [AS_VAR_SET([cv_Var],["yes"])], [AS_VAR_SET([cv_Var],["no"])] ) 
+      m4_ifnblank([$6],[dnl
+        LIBS="${mhd_check_func_SAVE_LIBS}"
+        AS_UNSET([mhd_check_func_SAVE_LIBS])
+      ])dnl
+    ])
+  AS_VAR_IF([cv_Var], ["yes"],
+            [AC_DEFINE([[HAVE_]]m4_bpatsubst(m4_toupper(m4_normalize(m4_translit([$1],[()],[  ]))),[[^A-Z0-9]],[_]),
+                       [1], [Define to 1 if you have the `]m4_normalize(m4_translit([$1],[()],[  ]))[' function.])
+            m4_n([$4])dnl
+            ], [$5])
+  AS_VAR_POPDEF([cv_Var])dnl
+])
+

src/microhttpd/daemon.c

@@ -6092,6 +6092,7 @@ MHD_start_daemon_va (unsigned int flags,
       listen_fd = daemon->listen_fd;
     }
 
+#ifdef HAVE_GETSOCKNAME
   if ( (0 == daemon->port) &&
        (0 == (*pflags & MHD_USE_NO_LISTEN_SOCKET)) )
     { /* Get port number. */
@@ -6160,6 +6161,7 @@ MHD_start_daemon_va (unsigned int flags,
           }
         }
     }
+#endif /* HAVE_GETSOCKNAME */
 
   if ( (MHD_INVALID_SOCKET != listen_fd) &&
        (! MHD_socket_nonblocking_ (listen_fd)) )