From a6f056d5c8b73acdec6502ebb87055c2158d12f1 Mon Sep 17 00:00:00 2001
From: Craig Andrews <candrews@integralblue.com>
Date: Thu, 17 Apr 2014 13:10:37 -0400
Subject: [PATCH] GRAILS-11333: Handle already absolute URLs

When a "uri" is provided to the link method and the "absolute" parameter is true, check if the provided uri is already absolute before trying to make it absolute.
---
 .../web/mapping/DefaultLinkGenerator.groovy   | 31 +++++++++++++------
 .../web/mapping/LinkGeneratorSpec.groovy      | 15 +++++++++
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/grails-web/src/main/groovy/org/codehaus/groovy/grails/web/mapping/DefaultLinkGenerator.groovy b/grails-web/src/main/groovy/org/codehaus/groovy/grails/web/mapping/DefaultLinkGenerator.groovy
index 6bebf0d3990..6d942ce504e 100644
--- a/grails-web/src/main/groovy/org/codehaus/groovy/grails/web/mapping/DefaultLinkGenerator.groovy
+++ b/grails-web/src/main/groovy/org/codehaus/groovy/grails/web/mapping/DefaultLinkGenerator.groovy
@@ -65,17 +65,19 @@ class DefaultLinkGenerator implements LinkGenerator, PluginManagerAware{
         def writer = new StringBuilder()
         // prefer URI attribute
         if (attrs.get(ATTRIBUTE_URI) != null) {
-            final base = handleAbsolute(attrs)
-            if (base != null) {
-                writer << base
-            }
-            else {
-                final cp = attrs.get(ATTRIBUTE_CONTEXT_PATH)
-                if (cp == null) cp = getContextPath()
-                if (cp != null)
-                    writer << cp
-            }
             final uriPath = attrs.get(ATTRIBUTE_URI).toString()
+            if(!isUriAbsolute(uriPath)){
+                final base = handleAbsolute(attrs)
+                if (base != null) {
+                    writer << base
+                }
+                else {
+                    final cp = attrs.get(ATTRIBUTE_CONTEXT_PATH)
+                    if (cp == null) cp = getContextPath()
+                    if (cp != null)
+                        writer << cp
+                }
+            }
             writer << uriPath
         }
         else {
@@ -244,6 +246,15 @@ class DefaultLinkGenerator implements LinkGenerator, PluginManagerAware{
         }
     }
 
+    private boolean isUriAbsolute(String uri){
+	try{
+            return new URI(uri).absolute
+	}catch(Exception e){
+            // assume unparseable URIs are absolute
+            return true
+        }
+    }
+
     /**
      * Get the declared URL of the server from config, or guess at localhost for non-production.
      */
diff --git a/grails-web/src/test/groovy/org/codehaus/groovy/grails/web/mapping/LinkGeneratorSpec.groovy b/grails-web/src/test/groovy/org/codehaus/groovy/grails/web/mapping/LinkGeneratorSpec.groovy
index 4f74c47a62e..e241c324da2 100644
--- a/grails-web/src/test/groovy/org/codehaus/groovy/grails/web/mapping/LinkGeneratorSpec.groovy
+++ b/grails-web/src/test/groovy/org/codehaus/groovy/grails/web/mapping/LinkGeneratorSpec.groovy
@@ -18,12 +18,27 @@ class LinkGeneratorSpec extends Specification {
 
     def baseUrl = "http://myserver.com/foo"
     def context = "/bar"
+    def someAbsoluteUrl = "http://www.grails.org/"
     def resource = null
     def linkParams = [:]
     def pluginManager
 
     def mainCssResource = [dir:'css', file:'main.css']
 
+    def "Test absolute link"() {
+        when:
+            linkParams.uri = someAbsoluteUrl
+            linkParams.absolute = true
+        then:
+            link == someAbsoluteUrl
+
+        when:
+            linkParams.uri = someAbsoluteUrl
+
+        then:
+            link == someAbsoluteUrl
+    }
+
     def "Test create link with root URI"() {
         when:
             linkParams.uri = '/'