From e567afbc584e32df6492d1ea29a65b583ca24e57 Mon Sep 17 00:00:00 2001
From: Michael Woerister <michaelwoerister@posteo>
Date: Thu, 14 Sep 2017 12:29:16 +0200
Subject: incr.comp.: Initialize IGNORED_ATTRS in StableHashingContext lazily.

---
 src/librustc/ich/impls_syntax.rs | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'src/librustc/ich/impls_syntax.rs')

diff --git a/src/librustc/ich/impls_syntax.rs b/src/librustc/ich/impls_syntax.rs
index a75527c14bd..4e3caca2b61 100644
--- a/src/librustc/ich/impls_syntax.rs
+++ b/src/librustc/ich/impls_syntax.rs
@@ -169,6 +169,11 @@ impl<'a, 'gcx, 'tcx> HashStable<StableHashingContext<'a, 'gcx, 'tcx>> for [ast::
     fn hash_stable<W: StableHasherResult>(&self,
                                           hcx: &mut StableHashingContext<'a, 'gcx, 'tcx>,
                                           hasher: &mut StableHasher<W>) {
+        if self.len() == 0 {
+            self.len().hash_stable(hcx, hasher);
+            return
+        }
+
         // Some attributes are always ignored during hashing.
         let filtered: AccumulateVec<[&ast::Attribute; 8]> = self
             .iter()
-- 
cgit 1.4.1-3-g733a5