fix image rendering.

lib/widget.js

@@ -6583,7 +6583,7 @@ Image.w3mdisplay = '/usr/lib/w3m/w3mimgdisplay';
 Image.prototype.render = function() {
   var ret = this._render();
   if (!ret) return;
-  this.setImage(this.options.file);
+  this.setImage(this.img);
   return ret;
 };
 

test/widget-image.js

@@ -6,16 +6,24 @@ screen = blessed.screen({
   smartCSR: true
 });
 
+blessed.image.w3mdisplay = '/does/not/exist';
+
+var file = process.argv[2] || __dirname + '/test-image.png';
+
 var img = blessed.image({
   parent: screen,
   left: 'center',
   top: 'center',
   width: 'shrink',
   height: 'shrink',
-  bg: 'green',
-  file: process.argv[2] || __dirname + '/test-image.png'
+  bg: 'green'
 });
 
+setTimeout(function() {
+  img.setImage(file);
+  screen.render();
+}, 1000);
+
 img.focus();
 
 screen.key('i', function() {