Claim address page security improvements

-Removed the ability to claim an address that has 0 transactions
-The "Claim" button is now disabled after submitting to help prevent double submissions

lib/database.js

@@ -460,35 +460,42 @@ module.exports = {
   },
 
   update_claim_name: function(hash, claim_name, cb) {
-    // check if the claim name is being removed
-    if (claim_name == null || claim_name == '') {
-      // remove the claim name
-      ClaimAddress.findOneAndDelete({a_id: hash}).then(() => {
-        // run processes after the claim name has been updated
-        after_update_claim_name(hash, claim_name, function() {
-          return cb('');
-        });
-      }).catch((err) => {
-        console.log(err);
-        return cb(err);
-      });
-    } else {
-      // add or update the claim name
-      ClaimAddress.updateOne({a_id: hash}, {
-        a_id: hash,
-        claim_name: claim_name
-      }, {
-        upsert: true
-      }).then(() => {
-        // run processes after the claim name has been updated
-        after_update_claim_name(hash, claim_name, function() {
-          return cb('');
-        });
-      }).catch((err) => {
-        console.log(err);
-        return cb(err);
-      });
-    }
+    // check if the address has received coins before by looking up the address in the local database
+    module.exports.get_address(hash, false, function(address) {
+      // check if the address was found in the local database
+      if (address) {
+        // check if the claim name is being removed
+        if (claim_name == null || claim_name == '') {
+          // remove the claim name
+          ClaimAddress.findOneAndDelete({a_id: hash}).then(() => {
+            // run processes after the claim name has been updated
+            after_update_claim_name(hash, claim_name, function() {
+              return cb('');
+            });
+          }).catch((err) => {
+            console.log(err);
+            return cb(err);
+          });
+        } else {
+          // add or update the claim name
+          ClaimAddress.updateOne({a_id: hash}, {
+            a_id: hash,
+            claim_name: claim_name
+          }, {
+            upsert: true
+          }).then(() => {
+            // run processes after the claim name has been updated
+            after_update_claim_name(hash, claim_name, function() {
+              return cb('');
+            });
+          }).catch((err) => {
+            console.log(err);
+            return cb(err);
+          });
+        }
+      } else
+        return cb('no_address');
+    });
   },
 
   update_richlist_claim_name: function(hash, claim_name, cb) {

views/claim_address.pug

@@ -47,6 +47,8 @@ block content
           ) {
             showClaimAlert('warning', 'The captcha validation has not been set', false);
           } else {
+            $('button.btn-success').attr('disabled', true);
+
             if ('#{selected_captcha_name}' == 'google_recaptcha2' && '#{settings.captcha.google_recaptcha2.captcha_type}' == 'invisible') {
               grecaptcha.execute();
             } else if ('#{selected_captcha_name}' == 'google_recaptcha3') {
@@ -117,6 +119,8 @@ block content
             // clear out the captcha to allow the form to be submitted again
             grecaptcha.reset();
           }
+
+          $('button.btn-success').attr('disabled', false);
         });
       }
       function onSubmit(token) {
@@ -124,6 +128,8 @@ block content
 
         // ensure the onSubmit event can fire again without needing to reload the page in the event that the server returns an error and the form must be submitted again
         grecaptcha.reset();
+
+        $('button.btn-success').attr('disabled', false);
       }
   .col-xs-12.col-md-12
     if settings.claim_address_page.page_header.show_img == true || settings.claim_address_page.page_header.show_title == true || settings.claim_address_page.page_header.show_description == true