Use PKG_CHECK_MODULES() to test for libcurl in configure

This is simpler and better (supports cross-compiling, manual override,
...) than doing it manually.

Also disable wxWebRequest completely under Unix if libcurl was not
found, as it's the only backend which can be used on non-MSW/Mac
platforms.

configure

@@ -983,6 +983,8 @@ DIRECTFB_CFLAGS
 GTK_CONFIG
 GTK_LIBS
 GTK_CFLAGS
+LIBCURL_LIBS
+LIBCURL_CFLAGS
 subdirs
 wxCFLAGS_C99
 LIBTIFF_LIBS
@@ -1388,6 +1390,8 @@ CCC
 PKG_CONFIG
 LIBTIFF_CFLAGS
 LIBTIFF_LIBS
+LIBCURL_CFLAGS
+LIBCURL_LIBS
 DIRECTFB_CFLAGS
 DIRECTFB_LIBS
 XMKMF
@@ -2402,6 +2406,10 @@ Some influential environment variables:
               C compiler flags for LIBTIFF, overriding pkg-config
   LIBTIFF_LIBS
               linker flags for LIBTIFF, overriding pkg-config
+  LIBCURL_CFLAGS
+              C compiler flags for LIBCURL, overriding pkg-config
+  LIBCURL_LIBS
+              linker flags for LIBCURL, overriding pkg-config
   DIRECTFB_CFLAGS
               C compiler flags for DIRECTFB, overriding pkg-config
   DIRECTFB_LIBS
@@ -22961,64 +22969,98 @@ if test "$wxUSE_LIBMSPACK" != "no"; then
 fi
 
 
-if test "$wxUSE_WEBREQUEST_CURL" != "no"; then
+if test "$wxUSE_WEBREQUEST_LIBCURL" != "no"; then
-    ac_fn_c_check_header_mongrel "$LINENO" "curl/curl.h" "ac_cv_header_curl_curl_h" "$ac_includes_default"
-if test "x$ac_cv_header_curl_curl_h" = xyes; then :
 
-fi
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for LIBCURL" >&5
+$as_echo_n "checking for LIBCURL... " >&6; }
 
-
+if test -n "$PKG_CONFIG"; then
-
+    if test -n "$LIBCURL_CFLAGS"; then
-    if test "$ac_cv_header_curl_curl_h" = "yes"; then
+        pkg_cv_LIBCURL_CFLAGS="$LIBCURL_CFLAGS"
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for curl_easy_init in -lcurl" >&5
+    else
-$as_echo_n "checking for curl_easy_init in -lcurl... " >&6; }
+        if test -n "$PKG_CONFIG" && \
-if ${ac_cv_lib_curl_curl_easy_init+:} false; then :
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libcurl\""; } >&5
-  $as_echo_n "(cached) " >&6
+  ($PKG_CONFIG --exists --print-errors "libcurl") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_LIBCURL_CFLAGS=`$PKG_CONFIG --cflags "libcurl" 2>/dev/null`
 else
-  ac_check_lib_save_LIBS=$LIBS
+  pkg_failed=yes
-LIBS="-lcurl  $LIBS"
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-/* Override any GCC internal prototype to avoid an error.
-   Use char because int might match the return type of a GCC
-   builtin and then its argument prototype would still apply.  */
-#ifdef __cplusplus
-extern "C"
-#endif
-char curl_easy_init ();
-int
-main ()
-{
-return curl_easy_init ();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_link "$LINENO"; then :
-  ac_cv_lib_curl_curl_easy_init=yes
-else
-  ac_cv_lib_curl_curl_easy_init=no
 fi
-rm -f core conftest.err conftest.$ac_objext \
-    conftest$ac_exeext conftest.$ac_ext
-LIBS=$ac_check_lib_save_LIBS
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_curl_curl_easy_init" >&5
-$as_echo "$ac_cv_lib_curl_curl_easy_init" >&6; }
-if test "x$ac_cv_lib_curl_curl_easy_init" = xyes; then :
-
-                CURL_LINK="-lcurl"
-                LIBS="$CURL_LINK $LIBS"
-                $as_echo "#define wxUSE_WEBREQUEST_CURL 1" >>confdefs.h
-
-
-fi
-
     fi
+else
+	pkg_failed=untried
+fi
+if test -n "$PKG_CONFIG"; then
+    if test -n "$LIBCURL_LIBS"; then
+        pkg_cv_LIBCURL_LIBS="$LIBCURL_LIBS"
+    else
+        if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libcurl\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libcurl") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_LIBCURL_LIBS=`$PKG_CONFIG --libs "libcurl" 2>/dev/null`
+else
+  pkg_failed=yes
+fi
+    fi
+else
+	pkg_failed=untried
+fi
 
-    if test -z "$CURL_LINK"; then
+
-        wxUSE_WEBREQUEST_CURL=no
+
+if test $pkg_failed = yes; then
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        LIBCURL_PKG_ERRORS=`$PKG_CONFIG --short-errors --errors-to-stdout --print-errors "libcurl"`
+        else
+	        LIBCURL_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "libcurl"`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$LIBCURL_PKG_ERRORS" >&5
+
+
+            wxUSE_WEBREQUEST_LIBCURL=no
+            { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
+$as_echo "not found" >&6; }
+
+
+elif test $pkg_failed = untried; then
+
+            wxUSE_WEBREQUEST_LIBCURL=no
+            { $as_echo "$as_me:${as_lineno-$LINENO}: result: not found" >&5
+$as_echo "not found" >&6; }
+
+
+else
+	LIBCURL_CFLAGS=$pkg_cv_LIBCURL_CFLAGS
+	LIBCURL_LIBS=$pkg_cv_LIBCURL_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+            CXXFLAGS="$LIBCURL_CFLAGS $CXXFLAGS"
+            LIBS="$LIBCURL_LIBS $LIBS"
+            $as_echo "#define wxUSE_WEBREQUEST_LIBCURL 1" >>confdefs.h
+
+
+fi
+
+    if test "$wxUSE_WEBREQUEST_LIBCURL" = "no"; then
+                                if test "$USE_WIN32" != 1 -a "$USE_DARWIN" != 1; then
+            { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: libcurl not found, wxWebRequest won't be available" >&5
+$as_echo "$as_me: WARNING: libcurl not found, wxWebRequest won't be available" >&2;}
+            wxUSE_WEBREQUEST=no
+        fi
     fi
 fi
 

configure.in

@@ -2924,20 +2924,27 @@ dnl ------------------------------------------------------------------------
 dnl Check for libcurl
 dnl ------------------------------------------------------------------------
 
-if test "$wxUSE_WEBREQUEST_CURL" != "no"; then
+if test "$wxUSE_WEBREQUEST_LIBCURL" != "no"; then
-    AC_CHECK_HEADER(curl/curl.h,,,[])
+    PKG_CHECK_MODULES(LIBCURL, [libcurl],
+        [
+            CXXFLAGS="$LIBCURL_CFLAGS $CXXFLAGS"
+            LIBS="$LIBCURL_LIBS $LIBS"
+            AC_DEFINE(wxUSE_WEBREQUEST_LIBCURL)
+        ],
+        [
+            wxUSE_WEBREQUEST_LIBCURL=no
+            AC_MSG_RESULT([not found])
+        ]
+    )
 
-    if test "$ac_cv_header_curl_curl_h" = "yes"; then
+    if test "$wxUSE_WEBREQUEST_LIBCURL" = "no"; then
-        AC_CHECK_LIB(curl, curl_easy_init,
+        dnl Under these platforms we have other, always available, backends for
-            [
+        dnl wxWebRequest, but under the others (i.e. generic Unix) libcurl is
-                CURL_LINK="-lcurl"
+        dnl the only way to implement wxWebRequest.
-                LIBS="$CURL_LINK $LIBS"
+        if test "$USE_WIN32" != 1 -a "$USE_DARWIN" != 1; then
-                AC_DEFINE(wxUSE_WEBREQUEST_CURL)
+            AC_MSG_WARN([libcurl not found, wxWebRequest won't be available])
-            ])
+            wxUSE_WEBREQUEST=no
-    fi
+        fi
-
-    if test -z "$CURL_LINK"; then
-        wxUSE_WEBREQUEST_CURL=no
     fi
 fi