From 39e7820520d08a35817ced858ae290a39e027bce Mon Sep 17 00:00:00 2001
From: nathangray <nathangray.bsc+github@gmail.com>
Date: Wed, 27 Feb 2019 09:03:28 -0700
Subject: [PATCH] Just send unified diff to client, not full old & new value

---
 api/src/Storage/History.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/api/src/Storage/History.php b/api/src/Storage/History.php
index f3be3807d1..f21393506c 100644
--- a/api/src/Storage/History.php
+++ b/api/src/Storage/History.php
@@ -260,6 +260,17 @@ class History
 					$row[$field] = explode(Tracking::ONE2N_SEPERATOR,$row[$field]);
 				}
 			}
+			if ($row['history_old_value'] !== Tracking::DIFF_MARKER && (
+				$this->needs_diff($row['history_status'], $row['history_old_value']) ||
+				$this->needs_diff($row['history_status'], $row['history_old_value'])
+			))
+			{
+				// Larger text stored with full old / new value - calculate diff and just send that
+				$diff = new \Text_Diff('auto', array(explode("\n",$row['history_new_value']), explode("\n",$row['history_old_value'])));
+				$renderer = new \Text_Diff_Renderer_unified();
+				$row['history_new_value'] = $renderer->render($diff);
+				$row['history_old_value'] = Tracking::DIFF_MARKER;
+			}
 			// Get information needed for proper display
 			if($row['history_appname'] == 'filemanager')
 			{
@@ -297,4 +308,10 @@ class History
 
 		return $total;
 	}
+
+	protected function needs_diff($name, $value)
+	{
+		return $name == 'note' || $name == 'description' ||
+			($value && (strlen($value) > 50 || strstr($value, "\n") !== FALSE));
+	}
 }