From 8281c7a137348f9e7392d35327283234ff4791a8 Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Wed, 17 Jan 2018 14:51:31 -0800
Subject: [PATCH] Fix the invalid file/directory location when getting file
 system entry for caching read directory results Fixes #20607

---
 src/compiler/core.ts                          |  7 ++++-
 src/compiler/sys.ts                           |  2 +-
 src/compiler/utilities.ts                     |  1 -
 .../unittests/tsserverProjectSystem.ts        | 26 +++++++++++++++++++
 4 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index d92a02661e8..5fa9a544f8f 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -20,6 +20,7 @@ namespace ts {
 
 /* @internal */
 namespace ts {
+    export const emptyArray: never[] = [] as never[];
     /** Create a MapLike with good performance. */
     function createDictionaryObject<T>(): MapLike<T> {
         const map = Object.create(/*prototype*/ null); // tslint:disable-line:no-null-keyword
@@ -3069,6 +3070,10 @@ namespace ts {
         readonly directories: string[];
     }
 
+    export const emptyFileSystemEntries: FileSystemEntries = {
+        files: emptyArray,
+        directories: emptyArray
+    };
     export function createCachedDirectoryStructureHost(host: DirectoryStructureHost): CachedDirectoryStructureHost {
         const cachedReadDirectoryResult = createMap<MutableFileSystemEntries>();
         const getCurrentDirectory = memoize(() => host.getCurrentDirectory());
@@ -3210,7 +3215,7 @@ namespace ts {
                 if (path === rootDirPath) {
                     return result;
                 }
-                return getCachedFileSystemEntries(path) || createCachedFileSystemEntries(dir, path);
+                return tryReadDirectory(dir, path) || emptyFileSystemEntries;
             }
         }
 
diff --git a/src/compiler/sys.ts b/src/compiler/sys.ts
index 841dba8a528..5293657a646 100644
--- a/src/compiler/sys.ts
+++ b/src/compiler/sys.ts
@@ -398,7 +398,7 @@ namespace ts {
                     return { files, directories };
                 }
                 catch (e) {
-                    return { files: [], directories: [] };
+                    return emptyFileSystemEntries;
                 }
             }
 
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index ffcdf42c67e..75083e159c5 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -2,7 +2,6 @@
 
 /* @internal */
 namespace ts {
-    export const emptyArray: never[] = [] as never[];
     export const resolvingEmptyArray: never[] = [] as never[];
     export const emptyMap: ReadonlyMap<never> = createMap<never>();
     export const emptyUnderscoreEscapedMap: ReadonlyUnderscoreEscapedMap<never> = emptyMap as ReadonlyUnderscoreEscapedMap<never>;
diff --git a/src/harness/unittests/tsserverProjectSystem.ts b/src/harness/unittests/tsserverProjectSystem.ts
index 68fbc1ecba0..2ac0945587a 100644
--- a/src/harness/unittests/tsserverProjectSystem.ts
+++ b/src/harness/unittests/tsserverProjectSystem.ts
@@ -4168,6 +4168,32 @@ namespace ts.projectSystem {
             // Since no file from the configured project is open, it would be closed immediately
             projectService.checkNumberOfProjects({ configuredProjects: 0, inferredProjects: 1 });
         });
+
+        it("should tolerate invalid include files that start in subDirectory", () => {
+            const projectFolder = "/user/username/projects/myproject";
+            const f = {
+                path: `${projectFolder}/src/server/index.ts`,
+                content: "let x = 1"
+            };
+            const config = {
+                path: `${projectFolder}/src/server/tsconfig.json`,
+                content: JSON.stringify({
+                    compiler: {
+                        module: "commonjs",
+                        outDir: "../../build"
+                    },
+                    include: [
+                        "../src/**/*.ts"
+                    ]
+                })
+            };
+            const host = createServerHost([f, config, libFile], { useCaseSensitiveFileNames: true });
+            const projectService = createProjectService(host);
+
+            projectService.openClientFile(f.path);
+            // Since no file from the configured project is open, it would be closed immediately
+            projectService.checkNumberOfProjects({ configuredProjects: 0, inferredProjects: 1 });
+        });
     });
 
     describe("tsserverProjectSystem reload", () => {