IDEA-374617 [debugger] Fix sporadic ConcurrentModificationException

Passing a mutable object probably wasn't the brightest idea.

GitOrigin-RevId: 144d09c18c4cf695087d0cf7220094b48fb160f6

java/debugger/impl/src/com/intellij/debugger/engine/JavaFramesListRendererUtils.kt

@@ -49,9 +49,10 @@ internal fun computeUiPresentation(
 
   descriptor.exactRecursiveIndex.asDeferred().await()?.let { index ->
     if (index > 0) {
-      container.append(" [$index]", SimpleTextAttributes.REGULAR_BOLD_ATTRIBUTES)
+      send(container.copy().apply {
+        append(" [$index]", SimpleTextAttributes.REGULAR_BOLD_ATTRIBUTES)
+      })
     }
   }
-  send(container)
   close()
 }.buffer(Channel.CONFLATED)

platform/xdebugger-api/api-dump-experimental.txt

@@ -29,6 +29,7 @@ a:com.intellij.xdebugger.frame.XStackFrame
 - append(com.intellij.ui.ColoredText):V
 - append(java.lang.String,com.intellij.ui.SimpleTextAttributes):V
 - append(java.lang.String,com.intellij.ui.SimpleTextAttributes,java.lang.Object):V
+- f:copy():com.intellij.xdebugger.frame.XStackFrameUiPresentationContainer
 - f:customizePresentation(com.intellij.ui.ColoredTextContainer):V
 - f:getFragments():java.util.List
 - f:getIcon():javax.swing.Icon

platform/xdebugger-api/src/com/intellij/xdebugger/frame/XStackFrameUiPresentationContainer.kt

@@ -50,4 +50,12 @@ class XStackFrameUiPresentationContainer : ColoredTextContainer {
       container.append(fragment, attrs)
     }
   }
+
+  fun copy(): XStackFrameUiPresentationContainer {
+    val copy = XStackFrameUiPresentationContainer()
+    copy.myIcon = myIcon
+    copy.myTooltipText = myTooltipText
+    copy.myFragments.addAll(myFragments)
+    return copy
+  }
 }