Replace "loadDraftAndPublishedComments()" with a Query

Summary: Ref T13513. Continue marching toward coherent query pathways for all access to inline comments.

Test Plan:
  - Viewed a commit and a path within that commit, as a user with unpublished inlines and a different user.
  - Saw appropriate inlines in all cases (published inlines, plus undeleted unpublished inlines authored by the current viewer).
  - Grepped for "loadDraftAndPublishedComments()".

Maniphest Tasks: T13513

Differential Revision: https://secure.phabricator.com/D21228

src/infrastructure/diff/query/PhabricatorDiffInlineCommentQuery.php

@@ -5,6 +5,8 @@ abstract class PhabricatorDiffInlineCommentQuery
 
   private $fixedStates;
   private $needReplyToComments;
+  private $visibleComments;
+  private $publishableComments;
 
   abstract protected function buildInlineCommentWhereClauseParts(
     AphrontDatabaseConnection $conn);
@@ -20,6 +22,16 @@ abstract class PhabricatorDiffInlineCommentQuery
     return $this;
   }
 
+  public function withVisibleComments($with_visible) {
+    $this->visibleComments = $with_visible;
+    return $this;
+  }
+
+  public function withPublishableComments($with_publishable) {
+    $this->publishableComments = $with_publishable;
+    return $this;
+  }
+
   protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {
     $where = parent::buildWhereClauseParts($conn);
     $alias = $this->getPrimaryTableAlias();
@@ -36,6 +48,72 @@ abstract class PhabricatorDiffInlineCommentQuery
         $this->fixedStates);
     }
 
+    $show_published = false;
+    $show_publishable = false;
+
+    if ($this->visibleComments !== null) {
+      if (!$this->visibleComments) {
+        throw new Exception(
+          pht(
+            'Querying for comments that are not visible is '.
+            'not supported.'));
+      }
+      $show_published = true;
+      $show_publishable = true;
+    }
+
+    if ($this->publishableComments !== null) {
+      if (!$this->publishableComments) {
+        throw new Exception(
+          pht(
+            'Querying for comments that are not publishable is '.
+            'not supported.'));
+      }
+      $show_publishable = true;
+    }
+
+    if ($show_publishable || $show_published) {
+      $clauses = array();
+
+      if ($show_published) {
+        // Published comments are always visible.
+        $clauses[] = qsprintf(
+          $conn,
+          '%T.transactionPHID IS NOT NULL',
+          $alias);
+      }
+
+      if ($show_publishable) {
+        $viewer = $this->getViewer();
+        $viewer_phid = $viewer->getPHID();
+
+        // If the viewer has a PHID, unpublished comments they authored and
+        // have not deleted are visible.
+        if ($viewer_phid) {
+          $clauses[] = qsprintf(
+            $conn,
+            '%T.authorPHID = %s
+              AND %T.isDeleted = 0
+              AND %T.transactionPHID IS NULL ',
+            $alias,
+            $viewer_phid,
+            $alias,
+            $alias);
+        }
+      }
+
+      // We can end up with a known-empty query if we (for example) query for
+      // publishable comments and the viewer is logged-out.
+      if (!$clauses) {
+        throw new PhabricatorEmptyQueryException();
+      }
+
+      $where[] = qsprintf(
+        $conn,
+        '%LO',
+        $clauses);
+    }
+
     return $where;
   }