---

yaml
---
r: 318399
b: refs/heads/master-rebranch
c: ef957ca
h: refs/heads/master
i:
  318397: bb7f876
  318395: fc7a3bc
  318391: db6ef61
  318383: 8406efe
  318367: 087a799
  318335: 113fbb2

Author: bob-wilson

[refs]

@@ -1457,4 +1457,4 @@ refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-02-a: ddd2b2976aa9bfde5f20fe37f6bd2
 refs/tags/swift-DEVELOPMENT-SNAPSHOT-2019-08-03-a: 171cc166f2abeb5ca2a4003700a8a78a108bd300
 refs/heads/benlangmuir-patch-1: baaebaf39d52f3bf36710d4fe40cf212e996b212
 refs/heads/i-do-redeclare: 8c4e6d5de5c1e3f0a2cedccf319df713ea22c48e
-refs/heads/master-rebranch: 9ec0a6cf8039bd87c1a27235f91085be36ce3f9a
+refs/heads/master-rebranch: ef957ca28e77326aef34f4df6bea201f2f1bf67c

branches/master-rebranch/utils/round-trip-syntax-test

@@ -76,9 +76,12 @@ class RoundTripTask(object):
 
         contents = ''.join(map(lambda l: l.decode('utf-8', errors='replace'),
                                open(self.input_filename).readlines()))
-        lines = difflib.unified_diff(contents,
-                                     self.stdout.decode('utf-8',
-                                                        errors='replace'),
+        stdout_contents = self.stdout.decode('utf-8', errors='replace')
+
+        if contents == stdout_contents:
+            return None
+
+        lines = difflib.unified_diff(contents, stdout_contents,
                                      fromfile=self.input_filename,
                                      tofile='-')
         diff = '\n'.join(line for line in lines)