Fix bugs on page load without parameters

static/canvas.js

@@ -91,8 +91,6 @@ let draw = function() {
 
       // Update download button
       document.querySelector('#save-image').href = canvas.toDataURL();
-    }, false);
-  });
 
       // Edit URL
       history.replaceState('', '', window.location.pathname + '?'
@@ -106,15 +104,10 @@ let draw = function() {
 
       // Update tweet button
       document.getElementById('tweet-button').href = 'https://twitter.com/intent/tweet?text=Soutenez La Quadrature du Net ! ' + encodeURIComponent(window.location.href);
+    }, false);
+  });
 }
 
-let bgColorElems = document.querySelectorAll('.colorpicker input[type="radio"], #step3 input[type="radio"], #step4 input[type="radio"]');
-for (let i = 0; i < bgColorElems.length; ++i) {
-  bgColorElems[i].onchange = draw;
-}
-document.getElementById('step2value').oninput = draw;
-document.getElementById('signature').oninput = draw;
-
 let navElems = document.querySelectorAll('nav > a');
 for (let i = 0; i < navElems.length; ++i) {
   navElems[i].onclick = function(e) {
@@ -139,6 +132,7 @@ window.onload = function() {
   document.querySelector('nav > a[href="' + hash + '"]').click();
 
   // Update inputs depending on URL params
+  if (window.location.search) {
     let splitParams = window.location.search.split('?')[1].split('&');
     let params = {};
     for (let i in splitParams) {
@@ -156,6 +150,15 @@ window.onload = function() {
       document.querySelector('input[name="icon"][value="' + params['icon'] + '"]').checked = true;
     if (params['signature'])
       document.getElementById('signature').value = params['signature'];
+  }
+
+  // Add event listeners to inputs
+  let bgColorElems = document.querySelectorAll('.colorpicker input[type="radio"], #step3 input[type="radio"], #step4 input[type="radio"]');
+  for (let i = 0; i < bgColorElems.length; ++i) {
+    bgColorElems[i].onchange = draw;
+  }
+  document.getElementById('step2value').oninput = draw;
+  document.getElementById('signature').oninput = draw;
 
   // Update canvas
   draw();