fix(panel/liveConsole): fix markers being in the wrong line

This happened when there was any line reflowing above it.
Context: xtermjs/xterm.js#5317

Author: tabarra

panel/src/pages/LiveConsole/LiveConsolePage.tsx

@@ -262,12 +262,13 @@ export default function LiveConsolePage() {
             }
 
             //Markers
+            let writeCallback: (() => void) | undefined;
             try {
                 const res = getTermLineEventData(line)
                     ?? getTermLineInitialData(line)
                     ?? getTermLineRtlData(line); //https://github.com/xtermjs/xterm.js/issues/701
                 if (res && res.markerData) {
-                    registerTermLineMarker(term, i, res.markerData);
+                    writeCallback = () => registerTermLineMarker(term, res.markerData);
                 }
                 if (res && res.newLine) {
                     line = res.newLine;
@@ -282,14 +283,14 @@ export default function LiveConsolePage() {
                 ? prefixColor + termPrefixRef.current.prefix
                 : '';
             if (i < lines.length - 1) {
-                term.writeln(prefix + line);
+                term.writeln(prefix + line, writeCallback);
                 termPrefixRef.current.lastEol = true;
             } else {
                 if (wasEolStripped) {
-                    term.writeln(prefix + line);
+                    term.writeln(prefix + line, writeCallback);
                     termPrefixRef.current.lastEol = true;
                 } else {
-                    term.write(prefix + line);
+                    term.write(prefix + line, writeCallback);
                     termPrefixRef.current.lastEol = false;
                 }
             }

panel/src/pages/LiveConsole/liveConsoleMarkers.ts

@@ -118,26 +118,15 @@ export const getTermLineInitialData = (line: string): TerminalMarkerGetterResult
 }
 
 
-/**
- * Gets the marker position based on the block index  
- * The marker position is always relative to cursor, but at the first render,
- * the cursor is = until all the writes are done, so we need to calculate the
- * marker position based on the block index
- */
-const getMarkerPos = (term: Terminal, blockIndex: number) => {
-    return term.buffer.active.cursorY === 0 ? blockIndex + 2 : 0;
-}
-
-
 /**
  * Registers a line marker & decoration
  */
 export const registerTermLineMarker = (
     term: Terminal,
-    blockIndex: number,
     markerData: TerminalMarkerData,
 ) => {
-    const marker = term.registerMarker(getMarkerPos(term, blockIndex));
+    //NOTE: as this is only called from a write callback, we will _always_ be one line ahead 
+    const marker = term.registerMarker(-1);
     const decoration = term.registerDecoration({ layer: 'top', marker });
     decoration && decoration.onRender((element) => {
         if (element.innerHTML) return; //terminal re-rendering