BUGFIX Overload validateURLSegment() in SubsitesVirtualPage to allow for same URLSegments as linked pages, as long as they only exist in a different subsite (only change the URLSegment if it already exists in the same subsite). (AIR-4)

code/SubsitesVirtualPage.php

@@ -105,6 +105,44 @@ class SubsitesVirtualPage extends VirtualPage {
 			$this->ExtraMeta = $this->ContentSource()->ExtraMeta ? $this->ContentSource()->ExtraMeta : $this->ExtraMeta; 
 		}
 	}
+	
+	function validURLSegment() {
+		$isValid = parent::validURLSegment();
+		
+		// Veto the validation rules if its false. In this case, some logic
+		// needs to be duplicated from parent to find out the exact reason the validation failed.
+		if(!$isValid) {
+			$IDFilter     = ($this->ID) ? "AND \"SiteTree\".\"ID\" <> $this->ID" :  null;
+			$parentFilter = null;
+
+			if(self::nested_urls()) {
+				if($this->ParentID) {
+					$parentFilter = " AND \"SiteTree\".\"ParentID\" = $this->ParentID";
+				} else {
+					$parentFilter = ' AND "SiteTree"."ParentID" = 0';
+				}
+			}
+			
+			Subsite::$disable_subsite_filter = true;
+			$existingPage = DataObject::get_one(
+				'SiteTree', 
+				"\"URLSegment\" = '$this->URLSegment' $IDFilter $parentFilter",
+				false // disable cache, it doesn't include subsite status in the key
+			);
+			Subsite::$disable_subsite_filter = false;
+			$existingPageInSubsite = DataObject::get_one(
+				'SiteTree', 
+				"\"URLSegment\" = '$this->URLSegment' $IDFilter $parentFilter",
+				false // disable cache, it doesn't include subsite status in the key
+			);
+
+			// If URL has been vetoed because of an existing page,
+			// be more specific and allow same URLSegments in different subsites
+			$isValid = !($existingPage && $existingPageInSubsite);
+		}
+		
+		return $isValid;
+	}
 }
 
 class SubsitesVirtualPage_Controller extends VirtualPage_Controller {

tests/SiteTreeSubsitesTest.php

@@ -130,6 +130,9 @@ class SiteTreeSubsitesTest extends SapphireTest {
 		);
 	}
 	
+	/**
+	 * Similar to {@link SubsitesVirtualPageTest->testSubsiteVirtualPageCanHaveSameUrlsegmentAsOtherSubsite()}.
+	 */
 	function testTwoPagesWithSameURLOnDifferentSubsites() {
 		// Set up a couple of pages with the same URL on different subsites
 		$s1 = $this->objFromFixture('Subsite','domaintest1');

tests/SubsitesVirtualPageTest.php

@@ -206,6 +206,44 @@ class SubsitesVirtualPageTest extends SapphireTest {
 		$onLive = Versioned::get_one_by_stage('SubsitesVirtualPage', 'Live', "\"SiteTree_Live\".\"ID\" = ".$vp2->ID);
 		$this->assertFalse($onLive, 'SVP has been removed from live');
 	}
+	
+	/**
+	 * Similar to {@link SiteTreeSubsitesTest->testTwoPagesWithSameURLOnDifferentSubsites()}
+	 * and {@link SiteTreeSubsitesTest->testPagesInDifferentSubsitesCanShareURLSegment()}.
+	 */
+	function testSubsiteVirtualPageCanHaveSameUrlsegmentAsOtherSubsite() {
+		Subsite::$write_hostmap = false;
+		$subsite1 = $this->objFromFixture('Subsite_Template', 'subsite1');
+		$subsite2 = $this->objFromFixture('Subsite_Template', 'subsite2');
+		Subsite::changeSubsite($subsite1->ID);
+		
+		$subsite1Page = $this->objFromFixture('SiteTree', 'subsite1_contactus');
+		$subsite1Page->URLSegment = 'contact-us';
+		$subsite1Page->write();
+		
+		// saving on subsite1, and linking to subsite1
+		$subsite1Vp = new SubsitesVirtualPage();
+		$subsite1Vp->CopyContentFromID = $subsite1Page->ID;
+		$subsite1Vp->SubsiteID = $subsite1->ID;
+		$subsite1Vp->write();
+		$this->assertNotEquals(
+			$subsite1Vp->URLSegment, 
+			$subsite1Page->URLSegment,
+			"Doesn't allow explicit URLSegment overrides when already existing in same subsite"
+		);
+		
+		// saving in subsite2 (which already has a page with URLSegment 'contact-us'), 
+		// but linking to a page in subsite1
+		$subsite2Vp = new SubsitesVirtualPage();
+		$subsite2Vp->CopyContentFromID = $subsite1Page->ID;
+		$subsite2Vp->SubsiteID = $subsite2->ID; 
+		$subsite2Vp->write();
+		$this->assertEquals(
+			$subsite2Vp->URLSegment, 
+			$subsite1Page->URLSegment,
+			"Does allow explicit URLSegment overrides when only existing in a different subsite"
+		);
+	}
 
 	function fixVersionNumberCache($page) {
 		$pages = func_get_args();