From 6a954f553c974ea0983cf4f9201d645e20401243 Mon Sep 17 00:00:00 2001
From: David Smith <david_smith@apple.com>
Date: Fri, 30 Jun 2023 14:27:26 -0700
Subject: [PATCH] Revert "Try using withContiguousStorageIfAvailable in
 RangeReplaceableCollection.append(contentsOf:) before falling back to a slow
 element-by-element loop. Fixes rdar://109059874"

This reverts commit 465aa22b81d96514f1813787fdfe9f23375deadc.
---
 stdlib/public/core/RangeReplaceableCollection.swift | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/stdlib/public/core/RangeReplaceableCollection.swift b/stdlib/public/core/RangeReplaceableCollection.swift
index 44c0df62aa7e5..fe5397d6aca34 100644
--- a/stdlib/public/core/RangeReplaceableCollection.swift
+++ b/stdlib/public/core/RangeReplaceableCollection.swift
@@ -453,15 +453,10 @@ extension RangeReplaceableCollection {
   @inlinable
   public mutating func append<S: Sequence>(contentsOf newElements: __owned S)
     where S.Element == Element {
-    
-    let done:Void? = newElements.withContiguousStorageIfAvailable {
-      replaceSubrange(endIndex..<endIndex, with: $0)
-    }
-      
-    if done == nil {
-      for element in newElements {
-        append(element)
-      }
+    let approximateCapacity = self.count + newElements.underestimatedCount
+    self.reserveCapacity(approximateCapacity)
+    for element in newElements {
+      append(element)
     }
   }