From b155fa847a6dd9d069bf6cb2e8e7dcebb16cda08 Mon Sep 17 00:00:00 2001
From: zhengbli <zhengbli@microsoft.com>
Date: Fri, 11 Mar 2016 16:18:40 -0800
Subject: [PATCH] Add comments

---
 src/compiler/sys.ts          | 3 +++
 src/server/editorServices.ts | 7 +++----
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index 6d7847ab588..c70985cd018 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -500,6 +500,9 @@ namespace ts {
                     for (const current of files) {
                         const name = combinePaths(path, current);
                         if (!contains(exclude, getCanonicalPath(name))) {
+                            // fs.statSync would throw an exception if the file is a symlink
+                            // whose linked file doesn't exist. fs.lstatSync would return a stat
+                            // object for the symlink file itself in this case
                             const stat = _fs.lstatSync(name);
                             if (stat.isFile()) {
                                 if (!extension || fileExtensionIs(name, extension)) {
diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 26b40b3d908..4b49c2944cd 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -1273,15 +1273,14 @@ namespace ts.server {
                     return error;
                 }
                 else {
+                    // if the project is too large, the root files might not have been all loaded if the total
+                    // program size reached the upper limit. In that case project.projectOptions.files should 
+                    // be more precise. However this would only happen for configured project.
                     const oldFileNames = project.projectOptions ? project.projectOptions.files : project.compilerService.host.roots.map(info => info.fileName);
                     const newFileNames = projectOptions.files;
                     const fileNamesToRemove = oldFileNames.filter(f => newFileNames.indexOf(f) < 0);
                     const fileNamesToAdd = newFileNames.filter(f => oldFileNames.indexOf(f) < 0);
 
-                    if (fileNamesToAdd.length === 0 && fileNamesToRemove.length === 0) {
-                        return;
-                    }
-
                     for (const fileName of fileNamesToRemove) {
                         const info = this.getScriptInfo(fileName);
                         if (info) {