From 73fa419a3ee2df74d4fb805117ec078d3ed58074 Mon Sep 17 00:00:00 2001
From: Yegor Bugayenko <yegor256@gmail.com>
Date: Fri, 2 Oct 2026 13:12:33 +0300
Subject: [PATCH] fix(#1528): limit unoptimizable-recursion self-calls to the
 formation's own scope

The self-call collection in unoptimizable-recursion.xsl matched every
reference to a formation's name anywhere below it, including inside
nested methods that build a fresh copy of their owner. Restrict it to
calls whose nearest enclosing formation is the one being checked.
---
 .../eolang/lints/design/unoptimizable-recursion.xsl   |  2 +-
 ...ed-method-that-builds-a-new-copy-of-its-owner.yaml | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 src/test/resources/org/eolang/lints/packs/single/unoptimizable-recursion/allows-a-nested-method-that-builds-a-new-copy-of-its-owner.yaml

diff --git a/src/main/resources/org/eolang/lints/design/unoptimizable-recursion.xsl b/src/main/resources/org/eolang/lints/design/unoptimizable-recursion.xsl
index 7cab376a3..ddabded37 100644
--- a/src/main/resources/org/eolang/lints/design/unoptimizable-recursion.xsl
+++ b/src/main/resources/org/eolang/lints/design/unoptimizable-recursion.xsl
@@ -92,7 +92,7 @@
       <xsl:for-each select="//o[eo:abstract(.) and @name and not(contains(@name, '🌵')) and o[@name='φ']]">
         <xsl:variable name="name" select="string(@name)"/>
         <xsl:variable name="root" select="o[@name='φ']"/>
-        <xsl:variable name="calls" select=".//o[eo:is-self-call(string(@base), $name) and not(ancestor::o[eo:test-name(@name)])]"/>
+        <xsl:variable name="calls" select=".//o[eo:is-self-call(string(@base), $name) and not(ancestor::o[eo:test-name(@name)]) and ancestor::o[eo:abstract(.)][1] is current()]"/>
         <xsl:variable name="loops" select="($root | $root//o)[eo:is-self-tail(string(@base), $name) and eo:tail(., $root)]"/>
         <xsl:variable name="elsewhere" select="$calls except ($root/descendant-or-self::o)"/>
         <xsl:if test="exists($calls) and empty($loops)">
diff --git a/src/test/resources/org/eolang/lints/packs/single/unoptimizable-recursion/allows-a-nested-method-that-builds-a-new-copy-of-its-owner.yaml b/src/test/resources/org/eolang/lints/packs/single/unoptimizable-recursion/allows-a-nested-method-that-builds-a-new-copy-of-its-owner.yaml
new file mode 100644
index 000000000..4e5597b84
--- /dev/null
+++ b/src/test/resources/org/eolang/lints/packs/single/unoptimizable-recursion/allows-a-nested-method-that-builds-a-new-copy-of-its-owner.yaml
@@ -0,0 +1,11 @@
+# SPDX-FileCopyrightText: Copyright (c) 2016-2026 Objectionary.com
+# SPDX-License-Identifier: MIT
+---
+sheets:
+  - /org/eolang/lints/design/unoptimizable-recursion.xsl
+defects: 0
+input: |
+  [x] > box
+    x > @
+    [y] > plus
+      box y > @