Fix buggy inode-handling

1. Very large inodes (those in excess of `Number.MAX_SAFE_INTEGER`) were
   getting clipped to a certain value, resulting in the wrong file being
   statted. This caused files to appear as directories (and vice versa).
   To solve this, we now call `fs.lstatSync` with its "bigint" option.

2. Files are now identified by a combination of device ID and inode; the
   latter alone isn't enough to uniquely identify a filesystem resource.

Author: Alhadis

lib/filesystem.js

@@ -12,7 +12,7 @@ class FileSystem {
 
 	constructor(){
 		this.paths = new PathMap();
-		this.inodes = new Map();
+		this.ids = new Map();
 		this.emitter = new Emitter();
 		this.disposables = new CompositeDisposable();
 	}
@@ -47,16 +47,16 @@ class FileSystem {
 		else{
 			lstat.lastError = null;
 			const stats = lstat(path);
-			const inode = stats ? stats.ino : null;
+			const id = stats ? [stats.dev, stats.ino].filter(Boolean).join(".") : null;
 
 			// Return null for nonexistent entities if `mustExist` is truthy
 			if(mustExist && lstat.lastError && "ENOENT" === lstat.lastError.code)
 				return null;
 
-			if(inode){
+			if(id){
 				// Don't reregister an entity after it's been moved
-				if(stats.nlink < 2 && this.inodes.has(inode)){
-					const resource = this.inodes.get(inode);
+				if(stats.nlink < 2 && this.ids.has(id)){
+					const resource = this.ids.get(id);
 					resource.setPath(path);
 					return resource;
 				}
@@ -76,16 +76,16 @@ class FileSystem {
 				: new File(path, stats);
 
 			this.paths.set(path, resource);
-			inode && this.inodes.set(inode, resource);
+			id && this.ids.set(id, resource);
 
 			const disposables = new CompositeDisposable(
 				resource.onDidDestroy(() => disposables.dispose()),
 				resource.onDidMove(paths => this.updatePath(paths.from, paths.to)),
 				new Disposable(() => {
 					this.paths.delete(resource.path);
 					this.paths.delete(resource.path.replace(/\//g, "\\"));
-					if(inode && resource.stats.nlink < 2)
-						this.inodes.delete(inode);
+					if(id && resource.stats.nlink < 2)
+						this.ids.delete(id);
 				})
 			);
 

lib/resource.js

@@ -110,7 +110,13 @@ class Resource{
 		if(stats){
 			this.pendingStats = false;
 			this.stats = stats;
-			this.type = EntityType.ALL & stats.mode;
+			this.type = EntityType.ALL & Number(stats.mode);
+			
+			// Identify resource uniquely, if possible
+			if(stats.ino){
+				const {dev, ino} = stats;
+				this.id = dev ? `${dev}.${ino}` : String(ino);
+			}
 
 			if(stats.isSymbolicLink())
 				this.isSymlink = true;
@@ -319,6 +325,7 @@ class Resource{
 
 Object.assign(Resource.prototype, {
 	destroyed: false,
+	id: null,
 	isDirectory: false,
 	isFile: false,
 	isSymlink: false,

lib/system-task.js

@@ -54,7 +54,7 @@ function exec(path, ops, meta = {}){
 		let stats = null;
 		if(OP_STAT & ops){
 			op = OP_STAT;
-			stats = fs.lstatSync(path);
+			stats = fs.lstatSync(path, {bigint: true});
 			emit("op:done", op, path, stats);
 		}
 

lib/utils.js

@@ -3,15 +3,26 @@
 const fs   = require("fs");
 const path = require("path");
 
+// Non-breaking fs functions
+const lstat    = nerf(fs.lstatSync);
+const realpath = nerf(fs.realpathSync);
+
 module.exports = {
 	nerf,
 	normalisePath,
 	sipFile,
 	statify,
-
-	// Non-breaking fs functions
-	lstat:    nerf(fs.lstatSync),
-	realpath: nerf(fs.realpathSync),
+	realpath,
+	lstat(path){
+		const stats  = lstat(path, {bigint: true});
+		stats.blocks = Number(stats.blocks);
+		stats.mode   = Number(stats.mode);
+		stats.nlink  = Number(stats.nlink);
+		stats.uid    = Number(stats.uid);
+		stats.gid    = Number(stats.gid);
+		stats.rdev   = Number(stats.rdev);
+		return stats;
+	},
 };