check if using a proxy is required, and if so, issue a warning if none is configured. p=fvanderbiest,me r=me (closes #3015)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@11038 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Lang/en.js

@@ -122,6 +122,9 @@ OpenLayers.Lang.en = {
     // console message
     'filterEvaluateNotImplemented': "evaluate is not implemented for this filter type.",
 
+    'proxyNeeded': "You probably need to set OpenLayers.ProxyHost to access ${url}."+
+        "See http://trac.osgeo.org/openlayers/wiki/FrequentlyAskedQuestions#ProxyHost",
+
     // **** end ****
     'end': ''
     

lib/OpenLayers/Lang/fr.js

@@ -75,6 +75,7 @@ OpenLayers.Lang["fr"] = OpenLayers.Util.applyDefaults({
 
     'pagePositionFailed': "OpenLayers.Util.pagePosition a échoué: l\'élément d\'id ${elemId} pourrait être mal positionné.",
 
-    'filterEvaluateNotImplemented': "évaluer n\'a pas encore été implémenté pour ce type de filtre."
+    'filterEvaluateNotImplemented': "évaluer n\'a pas encore été implémenté pour ce type de filtre.",
 
+    'proxyNeeded': "Vous avez très probablement besoin de renseigner OpenLayers.ProxyHost pour accéder à ${url}. Voir http://trac.osgeo.org/openlayers/wiki/FrequentlyAskedQuestions#ProxyHost"
 });

lib/OpenLayers/Request.js

@@ -35,6 +35,11 @@ OpenLayers.Request = {
         scope: null
     },
     
+    /**
+     * Constant: URL_SPLIT_REGEX
+     */
+    URL_SPLIT_REGEX: /([^:]*:)\/\/([^:]*:?[^@]*@)?([^:\/\?]*):?([^\/\?]*)/,
+    
     /**
      * APIProperty: events
      * {<OpenLayers.Events>} An events object that handles all 
@@ -128,11 +133,28 @@ OpenLayers.Request = {
                 url += separator + paramString;
             }
         }
-        if(config.proxy && (url.indexOf("http") == 0)) {
-            if(typeof config.proxy == "function") {
-                url = config.proxy(url);
+        var sameOrigin = !(url.indexOf("http") == 0);
+        var urlParts = !sameOrigin && url.match(this.URL_SPLIT_REGEX);
+        if (urlParts) {
+            var location = window.location;
+            sameOrigin =
+                urlParts[1] == location.protocol &&
+                urlParts[3] == location.hostname;
+            var uPort = urlParts[4], lPort = location.port;
+            if (uPort != 80 && uPort != "" || lPort != "80" && lPort != "") {
+                sameOrigin = sameOrigin && uPort == lPort;
+            }
+        }
+        if (!sameOrigin) {
+            if (config.proxy) {
+                if (typeof config.proxy == "function") {
+                    url = config.proxy(url);
+                } else {
+                    url = config.proxy + encodeURIComponent(url);
+                }
             } else {
-                url = config.proxy + encodeURIComponent(url);
+                OpenLayers.Console.warn(
+                    OpenLayers.i18n("proxyNeeded"), {url: url});
             }
         }
         request.open(