From 5fe5e2239519c89d2f566aff01e40a2e71715c30 Mon Sep 17 00:00:00 2001
From: Eric Lippmann <eric.lippmann@netways.de>
Date: Fri, 23 Jan 2015 16:00:15 +0100
Subject: [PATCH] doc: Support any link having a fragment except http(s) links
 for linking between headings

---
 modules/doc/doc/1-module-documentation.md   | 8 ++++++++
 modules/doc/library/Doc/SectionRenderer.php | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/modules/doc/doc/1-module-documentation.md b/modules/doc/doc/1-module-documentation.md
index 968dd32d7..edf20aac2 100644
--- a/modules/doc/doc/1-module-documentation.md
+++ b/modules/doc/doc/1-module-documentation.md
@@ -36,10 +36,18 @@ For linking between headings, place an anchor where you want to link to, e.g.:
 
     # <a id="heading"></a> Heading
 
+Please note that anchors have to be unique across all your Markdown documentation files.
+
 Now you can reference the anchor either in the same or **in another** Markdown documentation file, e.g.:
 
     This is a link to [Heading](#heading).
 
+Other tools support linking between headings by giving the filename plus the anchor to link to, e.g.:
+
+    This is a link to [About/Heading](1-about.md#heading.md)
+
+This syntax is also supported in Icinga Web 2.
+
 ## <a id="images"></a> Including Images
 
 Images must placed in the `img` directory beneath your module's `public` directory, e.g.:
diff --git a/modules/doc/library/Doc/SectionRenderer.php b/modules/doc/library/Doc/SectionRenderer.php
index 2fdaf8e90..f923783f6 100644
--- a/modules/doc/library/Doc/SectionRenderer.php
+++ b/modules/doc/library/Doc/SectionRenderer.php
@@ -232,7 +232,7 @@ class SectionRenderer extends Renderer
                 $html
             );
             $content[] = preg_replace_callback(
-                '/<a\s+(?P<attribs>[^>]*?\s+)?href="#(?P<fragment>[^"]+)"/',
+                '/<a\s+(?P<attribs>[^>]*?\s+)?href="(?:(?!http:\/\/)[^#]*)#(?P<fragment>[^"]+)"/',
                 array($callback, 'render'),
                 $html
             );