From 66c867395fa7f64e489896a9aee2129e4c716a88 Mon Sep 17 00:00:00 2001
From: Kamil Monicz <kamil@monicz.dev>
Date: Fri, 19 Dec 2025 01:03:30 +0000
Subject: [PATCH] Fix reserve pitfall in printString

Remove the per-call reserve() inside printString to avoid linear-growth reallocations when called in loops (e.g. printStrings). Derivation::unparse already pre-reserves a large buffer, so this remains efficient while preserving amortized growth behavior when the initial estimate is exceeded.
---
 src/libstore/derivations.cc | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index a4cdcb17a..76539e951 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -523,7 +523,6 @@ Derivation parseDerivation(
  */
 static void printString(std::string & res, std::string_view s)
 {
-    res.reserve(res.size() + s.size() * 2 + 2);
     res += '"';
     static constexpr auto chunkSize = 1024;
     std::array<char, 2 * chunkSize + 2> buffer;