Fix crash where src of image is not defined

lib/index.coffee

@@ -136,17 +136,19 @@ class EPub
             $(that).replaceWith($("<div>" + child + "</div>"))
 
       $("img").each (index, elem)->
-        url = $(elem).attr("src")
-        if image = self.options.images.find((element) -> element.url == url)
-          id = image.id
-          extension = image.extension
+        if url = $(elem).attr("src")
+          if image = self.options.images.find((element) -> element.url == url)
+            id = image.id
+            extension = image.extension
+          else
+            id = uuid()
+            mediaType = mime.getType url.replace /\?.*/, ""
+            extension = mime.getExtension mediaType
+            dir = content.dir
+            self.options.images.push {id, url, dir, mediaType, extension}
+          $(elem).attr("src", "images/#{id}.#{extension}")
         else
-          id = uuid()
-          mediaType = mime.getType url.replace /\?.*/, ""
-          extension = mime.getExtension mediaType
-          dir = content.dir
-          self.options.images.push {id, url, dir, mediaType, extension}
-        $(elem).attr("src", "images/#{id}.#{extension}")
+          $(elem).remove()
       content.data = $.xml()
       content
 

package.json

@@ -4,7 +4,8 @@
   "description": "A library to generate EPUB from HTML",
   "main": "index.js",
   "scripts": {
-    "test": "node test"
+    "test": "node test",
+    "compile": "coffee -c ."
   },
   "repository": {
     "type": "git",
@@ -36,5 +37,8 @@
     "superagent": "^3.8.2",
     "underscore": "^1.8.3",
     "uslug": "^1.0.4"
+  },
+  "devDependencies": {
+    "coffeescript": "^2.3.0"
   }
 }