Fix DocumentEngine line behaviors in Diffusion

Summary:
Ref T13105. Fixes some issues with line linking and highlighting under DocumentEngine:

  - Adding `$1-3` to the URI didn't work correctly with query parameters.
  - Reading `$1-3` from the URI didn't work correctly because Diffusion parses them slightly abnormally.

Test Plan: Clicked/dragged lines to select them. Observed URI. Reloaded page, got the right selection.

Reviewers: mydeveloperday

Reviewed By: mydeveloperday

Maniphest Tasks: T13105

Differential Revision: https://secure.phabricator.com/D19305

src/aphront/AphrontRequest.php

@@ -61,6 +61,10 @@ final class AphrontRequest extends Phobject {
    */
   public function getURILineRange($key, $limit) {
     $range = $this->getURIData($key);
+    return self::parseURILineRange($range, $limit);
+  }
+
+  public static function parseURILineRange($range, $limit) {
     if (!strlen($range)) {
       return null;
     }

src/applications/diffusion/document/DiffusionDocumentRenderingEngine.php

@@ -14,10 +14,6 @@ final class DiffusionDocumentRenderingEngine
     return $this->diffusionRequest;
   }
 
-  protected function getSelectedDocumentEngineKey() {
-    return $this->getRequest()->getStr('as');
-  }
-
   protected function newRefViewURI(
     PhabricatorDocumentRef $ref,
     PhabricatorDocumentEngine $engine) {
@@ -58,6 +54,15 @@ final class DiffusionDocumentRenderingEngine
       ));
   }
 
+  protected function getSelectedDocumentEngineKey() {
+    return $this->getRequest()->getStr('as');
+  }
+
+  protected function getSelectedLineRange() {
+    $range = $this->getDiffusionRequest()->getLine();
+    return AphrontRequest::parseURILineRange($range, 1000);
+  }
+
   protected function addApplicationCrumbs(
     PHUICrumbsView $crumbs,
     PhabricatorDocumentRef $ref = null) {

src/applications/files/document/render/PhabricatorDocumentRenderingEngine.php

@@ -54,7 +54,7 @@ abstract class PhabricatorDocumentRenderingEngine
     }
     $engine = $engines[$engine_key];
 
-    $lines = $request->getURILineRange('lines', 1000);
+    $lines = $this->getSelectedLineRange();
     if ($lines) {
       $engine->setHighlightedLines(range($lines[0], $lines[1]));
     }
@@ -157,18 +157,6 @@ abstract class PhabricatorDocumentRenderingEngine
       ->appendChild($viewport);
   }
 
-  abstract protected function newRefViewURI(
-    PhabricatorDocumentRef $ref,
-    PhabricatorDocumentEngine $engine);
-
-  abstract protected function newRefRenderURI(
-    PhabricatorDocumentRef $ref,
-    PhabricatorDocumentEngine $engine);
-
-  protected function getSelectedDocumentEngineKey() {
-    return $this->getRequest()->getURIData('engineKey');
-  }
-
   final public function newRenderResponse(PhabricatorDocumentRef $ref) {
     $request = $this->getRequest();
     $viewer = $request->getViewer();
@@ -280,6 +268,22 @@ abstract class PhabricatorDocumentRenderingEngine
     return $crumbs;
   }
 
+  abstract protected function newRefViewURI(
+    PhabricatorDocumentRef $ref,
+    PhabricatorDocumentEngine $engine);
+
+  abstract protected function newRefRenderURI(
+    PhabricatorDocumentRef $ref,
+    PhabricatorDocumentEngine $engine);
+
+  protected function getSelectedDocumentEngineKey() {
+    return $this->getRequest()->getURIData('engineKey');
+  }
+
+  protected function getSelectedLineRange() {
+    return $this->getRequest()->getURILineRange('lines', 1000);
+  }
+
   protected function addApplicationCrumbs(
     PHUICrumbsView $crumbs,
     PhabricatorDocumentRef $ref = null) {