Store forced connections in the Lisk connection cache

Summary:
In unit tests which use fixtures, we open transactions on every connection we establish. However, since we don't track connections that are established with "$force_new" (currently, only GlobalLock connections) we never close these transactions normally.

Instead of not tracking these connections, track them using unique keys so we'll never get a cache hit on them.

Test Plan: Built unit tests on top of this, had them stop dying from unclosed transactions.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1162

Differential Revision: https://secure.phabricator.com/D2938

src/infrastructure/storage/lisk/LiskDAO.php

@@ -302,9 +302,18 @@ abstract class LiskDAO {
    */
   protected function setEstablishedConnection(
     $mode,
-    AphrontDatabaseConnection $connection) {
+    AphrontDatabaseConnection $connection,
+    $force_unique = false) {
 
     $key = $this->getConnectionNamespace().':'.$mode;
+
+    if ($force_unique) {
+      $key .= ':unique';
+      while (isset(self::$connections[$key])) {
+        $key .= '!';
+      }
+    }
+
     self::$connections[$key] = $connection;
     return $this;
   }
@@ -1009,9 +1018,10 @@ abstract class LiskDAO {
       if (self::shouldIsolateAllLiskEffectsToTransactions()) {
         $connection->openTransaction();
       }
-      if (!$force_new) {
+      $this->setEstablishedConnection(
-        $this->setEstablishedConnection($mode, $connection);
+        $mode,
-      }
+        $connection,
+        $force_unique = $force_new);
     }
 
     return $connection;