From 0f3ecb7e500f9668a7f9ec74a43d8d565df6e2ea Mon Sep 17 00:00:00 2001
From: =?utf8?q?=C5=81ukasz=20Langa?= <lukasz@langa.pl>
Date: Fri, 27 Apr 2018 14:02:10 -0700
Subject: [PATCH] 18.4a4 hotfix: don't populate the cache on --check

Fixes #175
---
 README.md | 5 +++++
 black.py  | 6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 6cb50eb..bc8977b 100644
--- a/README.md
+++ b/README.md
@@ -522,6 +522,11 @@ More details can be found in [CONTRIBUTING](CONTRIBUTING.md).
 
 ## Change Log
 
+### 18.4a4
+
+* don't populate the cache on `--check` (#175)
+
+
 ### 18.4a3
 
 * added a "cache"; files already reformatted that haven't changed on disk
diff --git a/black.py b/black.py
index 5458198..4c5f0f0 100644
--- a/black.py
+++ b/black.py
@@ -43,7 +43,7 @@ from blib2to3 import pygram, pytree
 from blib2to3.pgen2 import driver, token
 from blib2to3.pgen2.parse import ParseError
 
-__version__ = "18.4a3"
+__version__ = "18.4a4"
 DEFAULT_LINE_LENGTH = 88
 
 # types
@@ -245,7 +245,7 @@ def reformat_one(
                 )
             ):
                 changed = Changed.YES
-            if write_back != WriteBack.DIFF and changed is not Changed.NO:
+            if write_back == WriteBack.YES and changed is not Changed.NO:
                 write_cache(cache, [src], line_length)
         report.done(src, changed)
     except Exception as exc:
@@ -312,7 +312,7 @@ async def schedule_formatting(
 
     if cancelled:
         await asyncio.gather(*cancelled, loop=loop, return_exceptions=True)
-    if write_back != WriteBack.DIFF and formatted:
+    if write_back == WriteBack.YES and formatted:
         write_cache(cache, formatted, line_length)
 
 
-- 
2.39.5