From 6e9880366fb2d6cccca532262e4c8218860203e4 Mon Sep 17 00:00:00 2001
From: Stefan Eissing <stefan@eissing.org>
Date: Fri, 14 Aug 2026 11:40:24 +0200
Subject: [PATCH] Revert "uint-bset: add slot0 member"

This reverts commit 743096a4964bf921f7b39cc7b739fd4fab6ad39c.

Closes #22581
---
 lib/uint-bset.c       | 21 ++++++---------------
 lib/uint-bset.h       |  1 -
 tests/unit/unit3211.c |  5 -----
 3 files changed, 6 insertions(+), 21 deletions(-)

diff --git a/lib/uint-bset.c b/lib/uint-bset.c
index f734f86ffd..55aedb234b 100644
--- a/lib/uint-bset.c
+++ b/lib/uint-bset.c
@@ -44,22 +44,14 @@ CURLcode Curl_uint32_bset_resize(struct uint32_bset *bset, uint32_t nmax)
 
   DEBUGASSERT(bset->init == CURL_UINT32_BSET_MAGIC);
   if(nslots != bset->nslots) {
-    uint64_t *slots;
-    if(nslots > 1) {
-      slots = curlx_calloc(nslots, sizeof(uint64_t));
-      if(!slots)
-        return CURLE_OUT_OF_MEMORY;
-    }
-    else {
-      bset->slot0 = 0;
-      slots = &bset->slot0;
-    }
+    uint64_t *slots = curlx_calloc(nslots, sizeof(uint64_t));
+    if(!slots)
+      return CURLE_OUT_OF_MEMORY;
 
-    if((bset->slots != slots) && nslots && bset->nslots) {
+    if(bset->slots) {
       memcpy(slots, bset->slots,
              (CURLMIN(nslots, bset->nslots) * sizeof(uint64_t)));
-      if(bset->slots != &bset->slot0)
-        curlx_free(bset->slots);
+      curlx_free(bset->slots);
     }
     bset->slots = slots;
     bset->nslots = nslots;
@@ -71,8 +63,7 @@ CURLcode Curl_uint32_bset_resize(struct uint32_bset *bset, uint32_t nmax)
 void Curl_uint32_bset_destroy(struct uint32_bset *bset)
 {
   DEBUGASSERT(bset->init == CURL_UINT32_BSET_MAGIC);
-  if(bset->slots != &bset->slot0)
-    curlx_free(bset->slots);
+  curlx_free(bset->slots);
   memset(bset, 0, sizeof(*bset));
 }
 
diff --git a/lib/uint-bset.h b/lib/uint-bset.h
index d4e2972ad1..ce0450c53c 100644
--- a/lib/uint-bset.h
+++ b/lib/uint-bset.h
@@ -39,7 +39,6 @@
 
 struct uint32_bset {
   uint64_t *slots;
-  uint64_t slot0;
   uint32_t nslots;
   uint32_t first_slot_used;
 #ifdef DEBUGBUILD
diff --git a/tests/unit/unit3211.c b/tests/unit/unit3211.c
index fea99301a1..0d1dde200d 100644
--- a/tests/unit/unit3211.c
+++ b/tests/unit/unit3211.c
@@ -126,10 +126,6 @@ static CURLcode test_unit3211(const char *arg)
 {
   UNITTEST_BEGIN_SIMPLE
 
-  static const uint32_t s0[] = {
-    /* spread numbers, some at slot edges */
-    0, 1, 4, 5, 8, 13, 17, 23, 24, 63,
-  };
   static const uint32_t s1[] = {
     /* spread numbers, some at slot edges */
     0, 1, 4, 17, 63, 64, 65, 66, 90, 99,
@@ -146,7 +142,6 @@ static CURLcode test_unit3211(const char *arg)
     120, 121, 122, 123, 124, 125, 126, 127,
   };
 
-  check_set("s0", 64, s0, CURL_ARRAYSIZE(s1));
   check_set("s1", 100, s1, CURL_ARRAYSIZE(s1));
   check_set("s2", 1000, s2, CURL_ARRAYSIZE(s2));