Merge pull request #528 from marcusklaas/chain-idempotence

Restore idempotence for chain formatting

1 files changed, 4 insertions, 4 deletions

diff --git a/src/chains.rs b/src/chains.rs
index 4716f545b3f..f004a5798c2 100644
--- a/src/chains.rs
+++ b/src/chains.rs
@@ -80,11 +80,11 @@ pub fn rewrite_chain(mut expr: &ast::Expr,
     let veto_single_line = if context.config.take_source_hints && subexpr_list.len() > 1 {
         // Look at the source code. Unless all chain elements start on the same
         // line, we won't consider putting them on a single line either.
-        let first_line_no = context.codemap.lookup_char_pos(subexpr_list[0].span.lo).line;
+        let last_span = context.snippet(mk_sp(subexpr_list[1].span.hi, total_span.hi));
+        let first_span = context.snippet(subexpr_list[1].span);
+        let last_iter = last_span.chars().take_while(|c| c.is_whitespace());
 
-        subexpr_list[1..]
-            .iter()
-            .any(|ex| context.codemap.lookup_char_pos(ex.span.hi).line != first_line_no)
+        first_span.chars().chain(last_iter).any(|c| c == '\n')
     } else {
         false
     };