Properly encode spans with a dummy location and non-root `SyntaxContext`

Previously, we would throw away the `SyntaxContext` of any span with a
dummy location during metadata encoding. This commit makes metadata Span
encoding consistent with incr-cache Span encoding - an 'invalid span'
tag is only used when it doesn't lose any information.

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index deca80f590f..1786969a889 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -162,7 +162,7 @@ impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for ExpnId {
 
 impl<'a, 'tcx> Encodable<EncodeContext<'a, 'tcx>> for Span {
     fn encode(&self, s: &mut EncodeContext<'a, 'tcx>) -> opaque::EncodeResult {
-        if self.is_dummy() {
+        if *self == rustc_span::DUMMY_SP {
             return TAG_INVALID_SPAN.encode(s);
         }