From 1dac9e71b525cb14eb358eaf0bc45b1554f5bf55 Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Fri, 22 May 2020 00:27:51 -0400
Subject: [PATCH] std.testing: fix a crash when printing diffs

---
 lib/std/testing.zig | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/lib/std/testing.zig b/lib/std/testing.zig
index 34bebad043..2d136d56c9 100644
--- a/lib/std/testing.zig
+++ b/lib/std/testing.zig
@@ -320,10 +320,11 @@ fn printWithVisibleNewlines(source: []const u8) void {
 }
 
 fn printLine(line: []const u8) void {
-    switch (line[line.len - 1]) {
+    if (line.len != 0) switch (line[line.len - 1]) {
         ' ', '\t' => warn("{}⏎\n", .{line}), // Carriage return symbol,
-        else => warn("{}\n", .{line}),
-    }
+        else => {},
+    };
+    warn("{}\n", .{line});
 }
 
 test "" {