From 8aa70cf6cd88b6103200d558c60295550c7b911d Mon Sep 17 00:00:00 2001
From: dweiller <4678790+dweiller@users.noreplay.github.com>
Date: Sun, 30 Apr 2023 14:38:11 +1000
Subject: [PATCH] sema: omit extraneous addition when safety is unwanted

---
 src/Sema.zig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Sema.zig b/src/Sema.zig
index bcb13ec6f0..17ba89a6e3 100644
--- a/src/Sema.zig
+++ b/src/Sema.zig
@@ -29284,6 +29284,7 @@ fn analyzeSlice(
     var end_is_len = uncasted_end_opt == .none;
     const end = e: {
         if (by_length and !end_is_len) {
+            if (!block.wantSafety()) break :e undefined;
             const len = try sema.coerce(block, Type.usize, uncasted_end_opt, end_src);
             const uncasted_end = try sema.analyzeArithmetic(block, .add, start, len, src, start_src, end_src, false);
             const end = try sema.coerce(block, Type.usize, uncasted_end, end_src);