Prevent infinite recursion in case of circular suppressed chains

#KT-37603

libraries/stdlib/js/src/kotlin/throwableExtensions.kt

@@ -15,7 +15,7 @@ package kotlin
  * - the detailed description of each throwable in the [Throwable.cause] chain.
  */
 @SinceKotlin("1.4")
-public actual fun Throwable.toStringWithTrace(): String = buildString { dumpStackTraceTo("", "", this) }
+public actual fun Throwable.toStringWithTrace(): String = buildString { dumpStackTraceTo("", "", this, arrayOf()) }
 
 /**
  * Adds the specified exception to the list of exceptions that were
@@ -43,19 +43,27 @@ public actual val Throwable.suppressedExceptions: List<Throwable>
     }
 
 
-private fun Throwable.dumpStackTraceTo(indent: String, qualifier: String, target: StringBuilder) {
-    this.dumpSelfTrace(indent, qualifier, target)
+private fun Array<Throwable>.hasSeen(exception: Throwable): Boolean = any { it === exception }
+
+private fun Throwable.dumpStackTraceTo(indent: String, qualifier: String, target: StringBuilder, visited: Array<Throwable>) {
+    this.dumpSelfTrace(indent, qualifier, target, visited) || return
 
     var cause = this.cause
     while (cause != null) {
         // TODO: should skip common stack frames
-        cause.dumpSelfTrace(indent, "Caused by: ", target)
+        cause.dumpSelfTrace(indent, "Caused by: ", target, visited)
         cause = cause.cause
     }
 }
 
-private fun Throwable.dumpSelfTrace(indent: String, qualifier: String, target: StringBuilder) {
+private fun Throwable.dumpSelfTrace(indent: String, qualifier: String, target: StringBuilder, visited: Array<Throwable>): Boolean {
     target.append(indent).append(qualifier)
+    if (visited.hasSeen(this)) {
+        target.append("[CIRCULAR REFERENCE, SEE ABOVE: ").append(this).append("]\n")
+        return false
+    }
+    visited.asDynamic().push(this)
+
     val stack = this.asDynamic().stack as String?
     if (stack != null) {
         if (indent.isNotEmpty()) {
@@ -76,7 +84,8 @@ private fun Throwable.dumpSelfTrace(indent: String, qualifier: String, target: S
     if (suppressed.isNotEmpty()) {
         val suppressedIndent = indent + '\t'
         for (s in suppressed) {
-            s.dumpStackTraceTo(suppressedIndent, "Suppressed: ", target)
+            s.dumpStackTraceTo(suppressedIndent, "Suppressed: ", target, visited)
         }
     }
+    return true
 }

libraries/stdlib/test/ExceptionTest.kt

@@ -127,6 +127,32 @@ class ExceptionTest {
             assertInTrace(causeSuppressed)
         }
 
+//        fail(topLevelTrace) // to dump the entire trace
+    }
+
+    @Test
+    fun circularSuppressedDetailedTrace() {
+        if (!supportsSuppressedExceptions) return
+
+        // Testing an exception of the following structure
+        // e1
+        //    -- suppressed: e3
+        //       -- suppressed: e1
+        // Caused by: e2
+        //    -- suppressed: e1
+        // Caused by: e3
+
+        val e3 = Exception("e3")
+        val e2 = Error("e2", e3)
+        val e1 = RuntimeException("e1", e2)
+        e1.addSuppressed(e3)
+        e3.addSuppressed(e1)
+        e2.addSuppressed(e1)
+
+        val topLevelTrace = e1.toStringWithTrace()
+        assertEquals(3, Regex.fromLiteral(e1.toString()).findAll(topLevelTrace).count(), topLevelTrace)
+        assertEquals(1, Regex.fromLiteral(e2.toString()).findAll(topLevelTrace).count(), topLevelTrace)
+        assertEquals(2, Regex.fromLiteral(e3.toString()).findAll(topLevelTrace).count(), topLevelTrace)
 //        fail(topLevelTrace) // to dump the entire trace
     }