1 files changed, 10 insertions, 0 deletions
diff --git a/lib/utils/page.js b/lib/utils/page.js
index fde2eaa..727f3b3 100644
--- a/lib/utils/page.js
+++ b/lib/utils/page.js
@@ -13,6 +13,8 @@ var fs = require('./fs');
 var batch = require('./batch');
 var code = require('./code');
 
+var parsableExtensions = require('gitbook-parsers').extensions;
+
 // Render a cheerio dom as html
 var renderDom = function($, dom, options) {
     if (!dom && $._root && $._root.children) {
@@ -196,11 +198,19 @@ function normalizeHtml(src, options) {
             var absolutePath = links.join(options.base, parts.pathname);
             var anchor = parts.hash || "";
 
+
             // If is in navigation relative: transform as content
             if (options.navigation[absolutePath]) {
                 absolutePath = options.book.contentLink(absolutePath);
             }
 
+            // If md/adoc/rst files is not in summary
+            // or for ebook, signal all files that are outside the summary
+            else if (_.contains(parsableExtensions, path.extname(absolutePath))
+            || _.contains(['epub', 'pdf', 'mobi'], options.book.options.generator)) {
+                options.book.log.warn.ln("page", options.input, "contains an hyperlink to resource outside spine '"+href+"'");
+            }
+
             // Transform as absolute
             href = links.toAbsolute("/"+absolutePath, options.base, options.output)+anchor;
         } else {