From 1d9d2d066e222510e54e4d3631eb056ee16e67be Mon Sep 17 00:00:00 2001
From: epriestley <git@epriestley.com>
Date: Wed, 22 Apr 2020 20:20:00 -0700
Subject: [PATCH] (stable) Don't pass "No newline at end of file." annotations
 to DocumentEngines as literal diff text

Summary: See PHI1707, which has a Jupyter notebook which fails to diff nicely when modified. The root cause seems to be that the document does not end in a newline.

Test Plan: Applied patch, diffed the file, got a Jupyter diff out of it.

Differential Revision: https://secure.phabricator.com/D21159
---
 .../parser/DifferentialChangesetParser.php    | 26 +++++++++++++------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/applications/differential/parser/DifferentialChangesetParser.php b/src/applications/differential/parser/DifferentialChangesetParser.php
index 92d5f23c1a..dc6d17acc3 100644
--- a/src/applications/differential/parser/DifferentialChangesetParser.php
+++ b/src/applications/differential/parser/DifferentialChangesetParser.php
@@ -1701,10 +1701,7 @@ final class DifferentialChangesetParser extends Phobject {
       if ($old_file) {
         $old_ref->setFile($old_file);
       } else {
-        $old_data = $this->old;
-        $old_data = ipull($old_data, 'text');
-        $old_data = implode('', $old_data);
-
+        $old_data = $this->getRawDocumentEngineData($this->old);
         $old_ref->setData($old_data);
       }
     }
@@ -1717,10 +1714,7 @@ final class DifferentialChangesetParser extends Phobject {
       if ($new_file) {
         $new_ref->setFile($new_file);
       } else {
-        $new_data = $this->new;
-        $new_data = ipull($new_data, 'text');
-        $new_data = implode('', $new_data);
-
+        $new_data = $this->getRawDocumentEngineData($this->new);
         $new_ref->setData($new_data);
       }
     }
@@ -1860,4 +1854,20 @@ final class DifferentialChangesetParser extends Phobject {
     return array($old_file, $new_file);
   }
 
+  private function getRawDocumentEngineData(array $lines) {
+    $text = array();
+
+    foreach ($lines as $line) {
+      // If this is a "No newline at end of file." annotation, don't hand it
+      // off to the DocumentEngine.
+      if ($line['type'] == '\\') {
+        continue;
+      }
+
+      $text[] = $line['text'];
+    }
+
+    return implode('', $text);
+  }
+
 }