diff -ru curl-8.13.0.orig/configure.ac curl-8.13.0/configure.ac
--- curl-8.13.0.orig/configure.ac	2025-04-02 07:47:41.000000000 +0200
+++ curl-8.13.0/configure.ac	2025-05-25 11:53:42.607216472 +0200
@@ -4078,7 +4078,6 @@
 CURL_CHECK_FUNC_ALARM
 CURL_CHECK_FUNC_BASENAME
 CURL_CHECK_FUNC_CLOSESOCKET
-CURL_CHECK_FUNC_CLOSESOCKET_CAMEL
 CURL_CHECK_FUNC_FCNTL
 CURL_CHECK_FUNC_FREEADDRINFO
 CURL_CHECK_FUNC_FSETXATTR
@@ -4092,7 +4091,6 @@
 CURL_CHECK_FUNC_GMTIME_R
 CURL_CHECK_FUNC_IOCTL
 CURL_CHECK_FUNC_IOCTLSOCKET
-CURL_CHECK_FUNC_IOCTLSOCKET_CAMEL
 CURL_CHECK_FUNC_MEMRCHR
 CURL_CHECK_FUNC_SIGACTION
 CURL_CHECK_FUNC_SIGINTERRUPT
diff -ru curl-8.13.0.orig/curl-config.in curl-8.13.0/curl-config.in
--- curl-8.13.0.orig/curl-config.in	2025-04-02 07:47:41.000000000 +0200
+++ curl-8.13.0/curl-config.in	2025-05-25 11:40:06.110600368 +0200
@@ -144,13 +144,13 @@
     if test "X@includedir@" = 'X/usr/include'; then
       echo '@LIBCURL_PC_CFLAGS@'
     else
-      echo "@LIBCURL_PC_CFLAGS@ -I@includedir@"
+      echo "@LIBCURL_PC_CFLAGS@"
     fi
     ;;
 
   --libs)
     if test "X@libdir@" != 'X/usr/lib' -a "X@libdir@" != 'X/usr/lib64'; then
-      curllibdir="-L@libdir@ "
+      curllibdir=""
     else
       curllibdir=''
     fi
diff -ru curl-8.13.0.orig/m4/curl-compilers.m4 curl-8.13.0/m4/curl-compilers.m4
--- curl-8.13.0.orig/m4/curl-compilers.m4	2025-04-02 07:47:41.000000000 +0200
+++ curl-8.13.0/m4/curl-compilers.m4	2025-05-25 12:02:19.604559677 +0200
@@ -42,37 +42,6 @@
   flags_opt_off="unknown"
   #
   flags_prefer_cppflags="no"
-  #
-  CURL_CHECK_COMPILER_DEC_C
-  CURL_CHECK_COMPILER_HPUX_C
-  CURL_CHECK_COMPILER_IBM_C
-  CURL_CHECK_COMPILER_INTEL_C
-  CURL_CHECK_COMPILER_CLANG
-  CURL_CHECK_COMPILER_GNU_C
-  case $host in
-    mips-sgi-irix*)
-      CURL_CHECK_COMPILER_SGI_MIPSPRO_C
-      CURL_CHECK_COMPILER_SGI_MIPS_C
-    ;;
-  esac
-  CURL_CHECK_COMPILER_SUNPRO_C
-  CURL_CHECK_COMPILER_TINY_C
-  #
-  if test "$compiler_id" = "unknown"; then
-  cat <<_EOF 1>&2
-***
-*** Warning: This configure script does not have information about the
-*** compiler you are using, relative to the flags required to enable or
-*** disable generation of debug info, optimization options or warnings.
-***
-*** Whatever settings are present in CFLAGS will be used for this run.
-***
-*** If you wish to help the curl project to better support your compiler
-*** you can report this and the required info on the libcurl development
-*** mailing list: https://lists.haxx.selistinfo/curl-library/
-***
-_EOF
-  fi
 ])
 
 
@@ -1419,15 +1388,13 @@
       tmp_CFLAGS="-fvisibility=hidden"
       supports_symbol_hiding="yes"
       ;;
-    GNU_C)
+    *)
       dnl Only gcc 3.4 or later
-      if test "$compiler_num" -ge "304"; then
         if $CC --help --verbose 2>/dev/null | grep fvisibility= >/dev/null ; then
           tmp_EXTERN="__attribute__((__visibility__(\"default\")))"
           tmp_CFLAGS="-fvisibility=hidden"
           supports_symbol_hiding="yes"
         fi
-      fi
       ;;
     INTEL_UNIX_C)
       dnl Only icc 9.0 or later
diff -ru curl-8.13.0.orig/m4/curl-functions.m4 curl-8.13.0/m4/curl-functions.m4
--- curl-8.13.0.orig/m4/curl-functions.m4	2025-04-02 07:47:41.000000000 +0200
+++ curl-8.13.0/m4/curl-functions.m4	2025-05-25 11:40:06.111107814 +0200
@@ -709,62 +709,6 @@
 ])
 
 
-dnl CURL_CHECK_FUNC_CLOSESOCKET_CAMEL
-dnl -------------------------------------------------
-dnl Verify if CloseSocket is available, prototyped, and
-dnl can be compiled. If all of these are true, and
-dnl usage has not been previously disallowed with
-dnl shell variable curl_disallow_closesocket_camel,
-dnl then HAVE_CLOSESOCKET_CAMEL will be defined.
-
-AC_DEFUN([CURL_CHECK_FUNC_CLOSESOCKET_CAMEL], [
-  AC_REQUIRE([CURL_INCLUDES_SYS_SOCKET])dnl
-  AC_REQUIRE([CURL_INCLUDES_BSDSOCKET])dnl
-  #
-  tst_compi_closesocket_camel="unknown"
-  tst_allow_closesocket_camel="unknown"
-  #
-  AC_MSG_CHECKING([if CloseSocket is compilable])
-  AC_COMPILE_IFELSE([
-    AC_LANG_PROGRAM([[
-      $curl_includes_bsdsocket
-      $curl_includes_sys_socket
-    ]],[[
-      if(0 != CloseSocket(0))
-        return 1;
-    ]])
-  ],[
-    AC_MSG_RESULT([yes])
-    tst_compi_closesocket_camel="yes"
-  ],[
-    AC_MSG_RESULT([no])
-    tst_compi_closesocket_camel="no"
-  ])
-  #
-  if test "$tst_compi_closesocket_camel" = "yes"; then
-    AC_MSG_CHECKING([if CloseSocket usage allowed])
-    if test "x$curl_disallow_closesocket_camel" != "xyes"; then
-      AC_MSG_RESULT([yes])
-      tst_allow_closesocket_camel="yes"
-    else
-      AC_MSG_RESULT([no])
-      tst_allow_closesocket_camel="no"
-    fi
-  fi
-  #
-  AC_MSG_CHECKING([if CloseSocket might be used])
-  if test "$tst_compi_closesocket_camel" = "yes" &&
-     test "$tst_allow_closesocket_camel" = "yes"; then
-    AC_MSG_RESULT([yes])
-    AC_DEFINE_UNQUOTED(HAVE_CLOSESOCKET_CAMEL, 1,
-      [Define to 1 if you have the CloseSocket camel case function.])
-    curl_cv_func_closesocket_camel="yes"
-  else
-    AC_MSG_RESULT([no])
-    curl_cv_func_closesocket_camel="no"
-  fi
-])
-
 dnl CURL_CHECK_FUNC_FCNTL
 dnl -------------------------------------------------
 dnl Verify if fcntl is available, prototyped, and