Add workaround for equivalent paths for watch option (#1895)

* Add workaround for equivalent paths for watch option

* Add comment

* Simplify path watching

app.go

@@ -427,7 +427,7 @@ func (app *app) loop() {
 				}
 			}
 
-			app.addWatchPaths()
+			app.watchDir(d)
 
 			app.ui.draw(app.nav)
 		case r := <-app.nav.regChan:
@@ -633,21 +633,17 @@ func (app *app) runShell(s string, args []string, prefix string) {
 	}
 }
 
-func (app *app) addWatchPaths() {
-	if !gOpts.watch || len(app.nav.dirs) == 0 {
+func (app *app) watchDir(dir *dir) {
+	if !gOpts.watch {
 		return
 	}
 
-	paths := make(map[string]bool)
-	for _, dir := range app.nav.dirs {
-		paths[dir.path] = true
-	}
+	app.watch.add(dir.path)
 
-	for _, file := range app.nav.currDir().allFiles {
+	// ensure dircounts are updated for child directories
+	for _, file := range dir.allFiles {
 		if file.IsDir() {
-			paths[file.path] = true
+			app.watch.add(file.path)
 		}
 	}
-
-	app.watch.add(paths)
 }

eval.go

@@ -195,7 +195,9 @@ func (e *setExpr) eval(app *app, args []string) {
 		if err == nil {
 			if gOpts.watch {
 				app.watch.start()
-				app.addWatchPaths()
+				for _, dir := range app.nav.dirCache {
+					app.watchDir(dir)
+				}
 			} else {
 				app.watch.stop()
 			}
@@ -582,7 +584,6 @@ func preChdir(app *app) {
 
 func onChdir(app *app) {
 	app.nav.addJumpList()
-	app.addWatchPaths()
 	if cmd, ok := gOpts.cmds["on-cd"]; ok {
 		cmd.eval(app, nil)
 	}

watch.go

@@ -64,16 +64,14 @@ func (watch *watch) stop() {
 	watch.events = nil
 }
 
-func (watch *watch) add(paths map[string]bool) {
+func (watch *watch) add(path string) {
 	if watch.watcher == nil {
 		return
 	}
 
-	for path := range paths {
-		// ignore /dev since write updates to /dev/tty causes high cpu usage
-		if path != "/dev" {
-			watch.watcher.Add(path)
-		}
+	// ignore /dev since write updates to /dev/tty causes high cpu usage
+	if path != "/dev" {
+		watch.watcher.Add(path)
 	}
 }
 
@@ -82,20 +80,26 @@ func (watch *watch) loop() {
 		select {
 		case ev := <-watch.events:
 			if ev.Has(fsnotify.Create) {
-				dir := filepath.Dir(ev.Name)
-				watch.addLoad(dir)
-				watch.addUpdate(dir)
+				for _, path := range watch.getSameDirs(filepath.Dir(ev.Name)) {
+					watch.addLoad(path)
+					watch.addUpdate(path)
+				}
 			}
 
 			if ev.Has(fsnotify.Remove) || ev.Has(fsnotify.Rename) {
-				watch.delChan <- ev.Name
-				dir := filepath.Dir(ev.Name)
-				watch.addLoad(dir)
-				watch.addUpdate(dir)
+				dir, file := filepath.Split(ev.Name)
+				for _, path := range watch.getSameDirs(dir) {
+					watch.delChan <- filepath.Join(path, file)
+					watch.addLoad(path)
+					watch.addUpdate(path)
+				}
 			}
 
 			if ev.Has(fsnotify.Write) || ev.Has(fsnotify.Chmod) {
-				watch.addUpdate(ev.Name)
+				dir, file := filepath.Split(ev.Name)
+				for _, path := range watch.getSameDirs(dir) {
+					watch.addUpdate(filepath.Join(path, file))
+				}
 			}
 		case <-watch.loadTimer.C:
 			for path := range watch.loads {
@@ -136,3 +140,32 @@ func (watch *watch) addUpdate(path string) {
 	}
 	watch.updates[path] = true
 }
+
+// Hacky workaround since fsnotify reports changes for only one path if a
+// directory is located at more than one path (e.g. bind mounts).
+func (watch *watch) getSameDirs(dir string) []string {
+	var paths []string
+
+	dirStat, err := os.Stat(dir)
+	if err != nil {
+		return nil
+	}
+
+	for _, path := range watch.watcher.WatchList() {
+		if path == dir {
+			paths = append(paths, path)
+			continue
+		}
+
+		stat, err := os.Stat(path)
+		if err != nil {
+			continue
+		}
+
+		if os.SameFile(stat, dirStat) {
+			paths = append(paths, path)
+		}
+	}
+
+	return paths
+}