From c0fab3d60e27e4d7a97223c9626db47e960ca047 Mon Sep 17 00:00:00 2001
From: sergeych <real.sergeych@gmail.com>
Date: Tue, 9 Dec 2025 07:33:05 +0100
Subject: [PATCH] bump version to 1.0.7-SNAPSHOT; fix potential infinite loops
 in Scope traversal

---
 lynglib/build.gradle.kts                      |  2 +-
 .../kotlin/net/sergeych/lyng/obj/ObjRef.kt    | 59 +++++++++++++++----
 lynglib/src/commonTest/kotlin/ScriptTest.kt   | 14 +++++
 3 files changed, 61 insertions(+), 14 deletions(-)

diff --git a/lynglib/build.gradle.kts b/lynglib/build.gradle.kts
index 84e2c68..43d938e 100644
--- a/lynglib/build.gradle.kts
+++ b/lynglib/build.gradle.kts
@@ -21,7 +21,7 @@ import org.jetbrains.kotlin.gradle.ExperimentalWasmDsl
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
 group = "net.sergeych"
-version = "1.0.6-SNAPSHOT"
+version = "1.0.7-SNAPSHOT"
 
 // Removed legacy buildscript classpath declarations; plugins are applied via the plugins DSL below
 
diff --git a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjRef.kt b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjRef.kt
index 0bec81c..def70a6 100644
--- a/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjRef.kt
+++ b/lynglib/src/commonMain/kotlin/net/sergeych/lyng/obj/ObjRef.kt
@@ -1351,15 +1351,21 @@ class FastLocalVarRef(
         if (owner.frameId != cachedOwnerFrameId) return false
         // Ensure owner is an ancestor (or same) of current
         var s: Scope? = current
+        var guard = 0
         while (s != null) {
             if (s === owner) return true
-            s = s.parent
+            val next = s.parent
+            // Defensive: break on self-parent or pathological cycles
+            if (next === s) return false
+            s = next
+            if (++guard > 4096) return false
         }
         return false
     }
 
     private fun resolveSlotInAncestry(scope: Scope): Int {
         var s: Scope? = scope
+        var guard = 0
         while (s != null) {
             val idx = s.getSlotIndexOf(name)
             if (idx != null) {
@@ -1368,7 +1374,10 @@ class FastLocalVarRef(
                 cachedSlot = idx
                 return idx
             }
-            s = s.parent
+            val next = s.parent
+            if (next === s) return -1
+            s = next
+            if (++guard > 4096) return -1
         }
         return -1
     }
@@ -1387,16 +1396,26 @@ class FastLocalVarRef(
         // Try per-frame local binding maps in the ancestry first (locals declared in frames)
         run {
             var s: Scope? = scope
+            var guard = 0
             while (s != null) {
                 s.localBindings[name]?.let { return it }
-                s = s.parent
+                val next = s.parent
+                if (next === s) break
+                s = next
+                if (++guard > 4096) break
             }
         }
         // Try to find a direct local binding in the current ancestry (without invoking name resolution that may prefer fields)
-        var s: Scope? = scope
-        while (s != null) {
-            s.objects[name]?.let { return it }
-            s = s.parent
+        run {
+            var s: Scope? = scope
+            var guard = 0
+            while (s != null) {
+                s.objects[name]?.let { return it }
+                val next = s.parent
+                if (next === s) break
+                s = next
+                if (++guard > 4096) break
+            }
         }
         // Fallback to standard name lookup (locals or closure chain) if the slot owner changed across suspension
         scope[name]?.let { return it }
@@ -1413,16 +1432,26 @@ class FastLocalVarRef(
         // Try per-frame local binding maps in the ancestry first
         run {
             var s: Scope? = scope
+            var guard = 0
             while (s != null) {
                 s.localBindings[name]?.let { return it.value }
-                s = s.parent
+                val next = s.parent
+                if (next === s) break
+                s = next
+                if (++guard > 4096) break
             }
         }
         // Try to find a direct local binding in the current ancestry first
-        var s: Scope? = scope
-        while (s != null) {
-            s.objects[name]?.let { return it.value }
-            s = s.parent
+        run {
+            var s: Scope? = scope
+            var guard = 0
+            while (s != null) {
+                s.objects[name]?.let { return it.value }
+                val next = s.parent
+                if (next === s) break
+                s = next
+                if (++guard > 4096) break
+            }
         }
         // Fallback to standard name lookup (locals or closure chain)
         scope[name]?.let { return it.value }
@@ -1443,6 +1472,7 @@ class FastLocalVarRef(
         // Try per-frame local binding maps in the ancestry first
         run {
             var s: Scope? = scope
+            var guard = 0
             while (s != null) {
                 val rec = s.localBindings[name]
                 if (rec != null) {
@@ -1450,7 +1480,10 @@ class FastLocalVarRef(
                     rec.value = newValue
                     return
                 }
-                s = s.parent
+                val next = s.parent
+                if (next === s) break
+                s = next
+                if (++guard > 4096) break
             }
         }
         // Fallback to standard name lookup
diff --git a/lynglib/src/commonTest/kotlin/ScriptTest.kt b/lynglib/src/commonTest/kotlin/ScriptTest.kt
index c761d6f..72745e5 100644
--- a/lynglib/src/commonTest/kotlin/ScriptTest.kt
+++ b/lynglib/src/commonTest/kotlin/ScriptTest.kt
@@ -4056,4 +4056,18 @@ class ScriptTest {
         """.trimIndent()
         )
     }
+
+    @Test
+    fun testHangOnPrintlnInMethods() = runTest {
+        eval("""
+            class T(someList) {
+                fun f() {
+                    val x = [...someList]
+                    println(x)
+                }
+            }
+            T([1,2]).f()
+        """)
+    }
+
 }