Return None from Span::join if in different files

diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs
index 41ccd88b4a887f559d3b2e2aeeb0d84a2d2f716e..386c12ba36ddfab22db964ca70090f18512ba39e 100644 (file)
--- a/src/libproc_macro/lib.rs
+++ b/src/libproc_macro/lib.rs
@@ -247,7 +247,7 @@ pub fn end(&self) -> LineColumn {
     #[unstable(feature = "proc_macro", issue = "38356")]
     pub fn join(&self, other: Span) -> Option<Span> {
         let self_loc = __internal::lookup_char_pos(self.0.lo());
-        let other_loc = __internal::lookup_char_pos(self.0.lo());
+        let other_loc = __internal::lookup_char_pos(other.0.lo());
 
         if self_loc.file.name != other_loc.file.name { return None }