From bbd7f5c85b4c9f547490786a1453eaaf20dd0696 Mon Sep 17 00:00:00 2001
From: Esteban Küber <esteban@kuber.com.ar>
Date: Mon, 4 Nov 2019 10:57:41 -0800
Subject: Do not ICE whith a precision flag in formatting str and no format
 arguments

---
 src/libsyntax_ext/format.rs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

(limited to 'src/libsyntax_ext/format.rs')

diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs
index 37310f46f7e..3c7f80aa399 100644
--- a/src/libsyntax_ext/format.rs
+++ b/src/libsyntax_ext/format.rs
@@ -374,10 +374,12 @@ impl<'a, 'b> Context<'a, 'b> {
                                 format!("are {} arguments", count)
                             },
                         ));
-                        e.span_label(
-                            self.args[pos].span,
-                            "this parameter corresponds to the precision flag",
-                        );
+                        if let Some(arg) = self.args.get(pos) {
+                            e.span_label(
+                                arg.span,
+                                "this parameter corresponds to the precision flag",
+                            );
+                        }
                         zero_based_note = true;
                     }
                     _ => {}
-- 
cgit 1.4.1-3-g733a5