setopt: add CURLOPT_CURLU

Allows an application to pass in a pre-parsed URL via a URL handle.

Closes #3227

lib/setopt.c

@@ -1204,6 +1204,12 @@ CURLcode Curl_vsetopt(struct Curl_easy *data, CURLoption option,
       return CURLE_BAD_FUNCTION_ARGUMENT;
     data->set.low_speed_time = arg;
     break;
+  case CURLOPT_CURLU:
+    /*
+     * pass CURLU to set URL
+     */
+    data->set.uh = va_arg(param, CURLU *);
+    break;
   case CURLOPT_URL:
     /*
      * The URL to fetch.

lib/transfer.c

@@ -1353,17 +1353,30 @@ void Curl_init_CONNECT(struct Curl_easy *data)
 CURLcode Curl_pretransfer(struct Curl_easy *data)
 {
   CURLcode result;
-  if(!data->change.url) {
+
+  if(!data->change.url && !data->set.uh) {
     /* we can't do anything without URL */
     failf(data, "No URL set!");
     return CURLE_URL_MALFORMAT;
   }
+
   /* since the URL may have been redirected in a previous use of this handle */
   if(data->change.url_alloc) {
     /* the already set URL is allocated, free it first! */
     Curl_safefree(data->change.url);
     data->change.url_alloc = FALSE;
   }
+
+  if(!data->change.url && data->set.uh) {
+    CURLUcode uc;
+    uc = curl_url_get(data->set.uh,
+                        CURLUPART_URL, &data->set.str[STRING_SET_URL], 0);
+    if(uc) {
+      failf(data, "No URL set!");
+      return CURLE_URL_MALFORMAT;
+    }
+  }
+
   data->change.url = data->set.str[STRING_SET_URL];
 
   /* Init the SSL session ID cache here. We do it here since we want to do it

lib/url.c

@@ -2026,7 +2026,13 @@ static CURLcode parseurlandfillconn(struct Curl_easy *data,
   Curl_up_free(data); /* cleanup previous leftovers first */
 
   /* parse the URL */
-  uh = data->state.uh = curl_url();
+  if(data->set.uh) {
+    uh = data->set.uh;
+  }
+  else {
+    uh = data->state.uh = curl_url();
+  }
+
   if(!uh)
     return CURLE_OUT_OF_MEMORY;
 
@@ -2043,15 +2049,17 @@ static CURLcode parseurlandfillconn(struct Curl_easy *data,
     data->change.url_alloc = TRUE;
   }
 
-  uc = curl_url_set(uh, CURLUPART_URL, data->change.url,
+  if(!data->set.uh) {
+    uc = curl_url_set(uh, CURLUPART_URL, data->change.url,
                     CURLU_GUESS_SCHEME |
                     CURLU_NON_SUPPORT_SCHEME |
                     (data->set.disallow_username_in_url ?
                      CURLU_DISALLOW_USER : 0) |
                     (data->set.path_as_is ? CURLU_PATH_AS_IS : 0));
-  if(uc) {
-    DEBUGF(infof(data, "curl_url_set rejected %s\n", data->change.url));
-    return Curl_uc_to_curlcode(uc);
+    if(uc) {
+      DEBUGF(infof(data, "curl_url_set rejected %s\n", data->change.url));
+      return Curl_uc_to_curlcode(uc);
+  }
   }
 
   uc = curl_url_get(uh, CURLUPART_SCHEME, &data->state.up.scheme, 0);
@@ -2193,6 +2201,7 @@ static CURLcode parseurlandfillconn(struct Curl_easy *data,
   return CURLE_OK;
 }
 
+
 /*
  * If we're doing a resumed transfer, we need to setup our stuff
  * properly.

lib/urldata.h

@@ -1728,6 +1728,7 @@ struct UserDefined {
   bool doh_get; /* use GET for DoH requests, instead of POST */
   multidone_func fmultidone;
   struct Curl_easy *dohfor; /* this is a DoH request for that transfer */
+  CURLU *uh; /* URL handle for the current parsed URL */
 };
 
 struct Names {