Added resolvePath helper to normalize and prepend the public_path and as needed

src/components/EntryListing/EntryListing.js

@@ -3,6 +3,7 @@ import ImmutablePropTypes from 'react-immutable-proptypes';
 import Waypoint from 'react-waypoint';
 import { Map } from 'immutable';
 import history from '../../routing/history';
+import { resolvePath } from '../../lib/pathHelper';
 import { selectFields, selectInferedField } from '../../reducers/collections';
 import { Card } from '../UI';
 import styles from './EntryListing.css';
@@ -39,9 +40,7 @@ export default class EntryListing extends React.Component {
     const label = entry.get('label');
     const title = label || entry.getIn(['data', inferedFields.titleField]);
     let image = entry.getIn(['data', inferedFields.imageField]);
-    if (image && image.indexOf('/') === -1) {
-      image = `/${ publicFolder }/${ image }`;
-    }
+    image = resolvePath(image, publicFolder);
     return (
       <Card
         key={entry.get('slug')}

src/lib/pathHelper.js

@@ -0,0 +1,18 @@
+const absolutePath = new RegExp('^(?:[a-z]+:)?//', 'i');
+const normalizePath = path => path.replace(/[\\\/]+/g, '/');
+
+export function resolvePath(path, basePath) { // eslint-disable-line
+  // No path provided, skip
+  if (!path) return null;
+
+  // It's an absolute path.
+  if (absolutePath.test(path)) return normalizePath(path);
+
+  if (path.indexOf('/') === -1) {
+    // It's a single file name, no directories. Prepend public folder
+    return normalizePath(`/${ basePath }/${ path }`);
+  }
+
+  // It's a relative path. Prepend a forward slash.
+  return normalizePath(`/${ path }`);
+}

src/reducers/medias.js

@@ -1,4 +1,5 @@
 import { Map } from 'immutable';
+import { resolvePath } from '../lib/pathHelper';
 import { ADD_MEDIA, REMOVE_MEDIA } from '../actions/media';
 import MediaProxy from '../valueObjects/MediaProxy';
 
@@ -17,13 +18,14 @@ const medias = (state = Map(), action) => {
 export default medias;
 
 export const getMedia = (publicFolder, state, path) => {
+  // No path provided, skip
+  if (!path) return null;
+
   if (state.has(path)) {
+    // There is already a MediaProxy in memmory for this path. Use it.
     return state.get(path);
   }
 
-  let localPath = path;
-  if (path && path.indexOf('/') === -1) {
-    localPath = `/${ publicFolder }/${ localPath }`;
-  }
-  return new MediaProxy(localPath, null, true);
+  // Create a new MediaProxy (for consistency) and return it.
+  return new MediaProxy(resolvePath(path, publicFolder), null, true);
 };