From f5ad8a0b9ed5abc849efee04c25b7c7335fc0c9e Mon Sep 17 00:00:00 2001
From: Afonso Oliveira <afonso.oliveira707@gmail.com>
Date: Wed, 23 Sep 2026 09:19:45 +0100
Subject: [PATCH] Stop cyclic shell color references

Resolve color references iteratively and use the caller's fallback when a reference repeats. Preserve normal palette roles, color parsing and gradient first stops.

Reported-by: Aleksej <aleksejhairov@yandex.ru>
---
 shell/Commons/Color.qml              |  8 ++++-
 test/shell.d/color-reference-test.sh | 52 ++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100755 test/shell.d/color-reference-test.sh

diff --git a/shell/Commons/Color.qml b/shell/Commons/Color.qml
index 54163a40..4fd2452b 100644
--- a/shell/Commons/Color.qml
+++ b/shell/Commons/Color.qml
@@ -49,9 +49,15 @@ QtObject {
   }
 
   function flatColor(value, fallback) {
+    var seen = Object.create(null)
     var token = firstColorToken(value)
     var role = String(token || "").replace(/^\s+|\s+$/g, "").toLowerCase()
-    if (root.shellValues[role] && root.shellValues[role] !== token) return flatColor(root.shellValues[role], fallback)
+    while (root.shellValues[role] && root.shellValues[role] !== token) {
+      if (seen[role]) return fallback
+      seen[role] = true
+      token = firstColorToken(root.shellValues[role])
+      role = String(token || "").replace(/^\s+|\s+$/g, "").toLowerCase()
+    }
     if (role === "foreground" || role === "text") return root.foreground
     if (role === "accent") return root.accent
     if (role === "urgent") return root.urgent
diff --git a/test/shell.d/color-reference-test.sh b/test/shell.d/color-reference-test.sh
new file mode 100755
index 00000000..498f6789
--- /dev/null
+++ b/test/shell.d/color-reference-test.sh
@@ -0,0 +1,52 @@
+#!/bin/bash
+set -euo pipefail
+source "$(dirname "$0")/base-test.sh"
+
+run_node_test <<'JS'
+const fs = require('fs')
+const vm = require('vm')
+
+const source = fs.readFileSync(path.join(root, 'shell/Commons/Color.qml'), 'utf8')
+const geometry = fs.readFileSync(path.join(root, 'shell/Commons/BorderGeometry.js'), 'utf8').replace(/^\.pragma library\n/, '')
+const palette = { foreground: '#eeeeee', background: '#111111', accent: '#abcdef', urgent: '#ff0000', muted: '#777777' }
+const context = vm.createContext({ root: { ...palette, shellValues: {} }, Geometry: {} })
+vm.runInNewContext(geometry, context.Geometry)
+for (const name of ['firstColorToken', 'flatColor', 'parseShell']) {
+  const fn = source.match(new RegExp(`  function ${name}\\([^]*?\\n  }`))
+  if (!fn) fail(`Color.qml provides ${name}`)
+  vm.runInContext(fn[0], context)
+}
+
+function check(values, input, expected, description) {
+  context.root.shellValues = values
+  context.input = input
+  const result = vm.runInContext('flatColor(input, "#123456")', context, { timeout: 1000 })
+  assertEqual(result, expected, description)
+}
+
+const cycle = context.parseShell('[bar]\nbackground = "menu.background"\n[menu]\nbackground = "bar.background"')
+check(cycle, 'bar.background', '#123456', 'two-entry theme cycle returns the supplied fallback')
+check({ 'a.color': 'b.color', 'b.color': 'c.color', 'c.color': 'a.color' }, 'a.color', '#123456', 'longer cycle returns fallback')
+check({ 'start.color': 'a.color', 'a.color': 'b.color', 'b.color': 'a.color' }, 'start.color', '#123456', 'chain entering a cycle returns fallback')
+check({ 'a.color': 'a.color' }, 'a.color', '#123456', 'direct self-reference returns fallback')
+check({ 'a.color': ' A.COLOR ' }, 'a.color', '#123456', 'normalized self-reference returns fallback')
+check({ 'a.color': '45deg b.color #ffffff', 'b.color': 'a.color' }, 'a.color', '#123456', 'gradient first-stop cycle returns fallback')
+
+check({ 'a.color': 'b.color', 'b.color': '#abcdef' }, 'a.color', '#abcdef', 'acyclic references preserve the final color')
+check({ 'a.color': ' B.COLOR ', 'b.color': '#abcdef' }, 'A.COLOR', '#abcdef', 'each reference keeps case and whitespace normalization')
+check({ 'a.color': 'b.color', 'b.color': 'accent' }, 'a.color', palette.accent, 'acyclic references preserve palette roles')
+check({ 'a.color': '45deg rgba(11223380) #ffffff' }, 'a.color', '#11223380', 'referenced gradient keeps its first color and alpha')
+check({ 'a.color': 'missing.color' }, 'a.color', '#123456', 'missing reference returns fallback')
+check({}, '', '#123456', 'empty input returns fallback')
+for (const [role, color] of Object.entries(palette)) check({}, role, color, `palette role ${role} is unchanged`)
+check({}, 'text', palette.foreground, 'text alias is unchanged')
+for (const [input, output] of [['#abc', '#aabbcc'], ['#abcdef', '#abcdef'], ['rgb(abcdef)', '#abcdef'], ['rgba(11223380)', '#11223380']]) {
+  check({}, input, output, `direct color ${input} is unchanged`)
+}
+
+const chain = {}
+for (let i = 0; i < 10000; i++) chain[`chain.c${i}`] = `chain.c${i + 1}`
+chain['chain.c10000'] = '#abcdef'
+check(chain, 'chain.c0', '#abcdef', 'long acyclic chains do not exhaust the call stack')
+check({ 'a.color': '#abcdef' }, 'a.color', '#abcdef', 'visited references do not leak between resolutions')
+JS