Make application aware it saved the buffer and not something else (#4314)

Make application aware it saved the buffer and something else

src/components/FileTree.tsx

@@ -140,6 +140,13 @@ const FileTreeItem = ({
     async (eventType, path) => {
       // Don't try to read a file that was removed.
       if (isCurrentFile && eventType !== 'unlink') {
+        // Prevents a cyclic read / write causing editor problems such as
+        // misplaced cursor positions.
+        if (codeManager.writeCausedByAppCheckedInFileTreeFileSystemWatcher) {
+          codeManager.writeCausedByAppCheckedInFileTreeFileSystemWatcher = false
+          return
+        }
+
         let code = await window.electron.readFile(path, { encoding: 'utf-8' })
         code = normalizeLineEndings(code)
         codeManager.updateCodeStateEditor(code)

src/lang/codeManager.ts

@@ -20,6 +20,8 @@ export default class CodeManager {
   private _hotkeys: { [key: string]: () => void } = {}
   private timeoutWriter: ReturnType<typeof setTimeout> | undefined = undefined
 
+  public writeCausedByAppCheckedInFileTreeFileSystemWatcher = false
+
   constructor() {
     if (isDesktop()) {
       this.code = ''
@@ -120,6 +122,7 @@ export default class CodeManager {
       // and file-system watchers which read, will receive empty data during
       // writes.
       clearTimeout(this.timeoutWriter)
+      this.writeCausedByAppCheckedInFileTreeFileSystemWatcher = true
       this.timeoutWriter = setTimeout(() => {
         // Wait one event loop to give a chance for params to be set
         // Save the file to disk