accounts: fix missing wallet drop (#35133)

The drop helper uses sort.Search on the sorted wallet list, but the
returned index can point at the next greater wallet when the target URL
is missing. Fix this by rewriting the drop to use slices.DeleteFunc and a map.

---------

Co-authored-by: Felix Lange <fjl@twurst.com>

accounts/manager.go

@@ -18,6 +18,7 @@ package accounts
 
 import (
 	"reflect"
+	"slices"
 	"sort"
 	"sync"
 
@@ -254,13 +255,12 @@ func merge(slice []Wallet, wallets ...Wallet) []Wallet {
 // drop is the counterpart of merge, which looks up wallets from within the sorted
 // cache and removes the ones specified.
 func drop(slice []Wallet, wallets ...Wallet) []Wallet {
-	for _, wallet := range wallets {
-		n := sort.Search(len(slice), func(i int) bool { return slice[i].URL().Cmp(wallet.URL()) >= 0 })
-		if n == len(slice) {
-			// Wallet not found, may happen during startup
-			continue
-		}
-		slice = append(slice[:n], slice[n+1:]...)
+	remove := make(map[URL]struct{}, len(wallets))
+	for _, w := range wallets {
+		remove[w.URL()] = struct{}{}
 	}
-	return slice
+	return slices.DeleteFunc(slice, func(w Wallet) bool {
+		_, ok := remove[w.URL()]
+		return ok
+	})
 }

accounts/manager_test.go

@@ -0,0 +1,47 @@
+// Copyright 2026 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package accounts
+
+import "testing"
+
+type managerTestWallet struct {
+	Wallet
+	url URL
+}
+
+func (w managerTestWallet) URL() URL {
+	return w.url
+}
+
+func TestDropMissingWallet(t *testing.T) {
+	t.Parallel()
+
+	wallets := []Wallet{
+		managerTestWallet{url: URL{Scheme: "test", Path: "a"}},
+		managerTestWallet{url: URL{Scheme: "test", Path: "c"}},
+	}
+	dropped := drop(wallets, managerTestWallet{url: URL{Scheme: "test", Path: "b"}})
+
+	if len(dropped) != len(wallets) {
+		t.Fatalf("drop removed wallet for missing URL: got %d wallets, want %d", len(dropped), len(wallets))
+	}
+	for i := range dropped {
+		if got, want := dropped[i].URL(), wallets[i].URL(); got != want {
+			t.Fatalf("wallet %d mismatch: got %v, want %v", i, got, want)
+		}
+	}
+}