Dont rely on link metdata being valid file path

src/Workspaces/Core/Desktop/Workspace/MSBuild/MSBuildWorkspace.cs

@@ -636,7 +636,7 @@ private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectF
 
             var projectId = this.GetOrCreateProjectId(projectFilePath);
 
-            var name = Path.GetFileNameWithoutExtension(projectFilePath);
+            var projectName = Path.GetFileNameWithoutExtension(projectFilePath);
 
             var projectFile = await loader.LoadProjectFileAsync(projectFilePath, _properties, cancellationToken).ConfigureAwait(false);
             var projectFileInfo = await projectFile.GetProjectFileInfoAsync(cancellationToken).ConfigureAwait(false);
@@ -660,10 +660,14 @@ private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectF
             var docs = new List<DocumentInfo>();
             foreach (var docFileInfo in docFileInfos)
             {
+                string name;
+                ImmutableArray<string> folders;
+                GetDocumentNameAndFolders(docFileInfo.LogicalPath, out name, out folders);
+
                 docs.Add(DocumentInfo.Create(
                     DocumentId.CreateNewId(projectId, debugName: docFileInfo.FilePath),
-                    Path.GetFileName(docFileInfo.LogicalPath),
-                    GetDocumentFolders(docFileInfo.LogicalPath),
+                    name,
+                    folders,
                     projectFile.GetSourceCodeKind(docFileInfo.FilePath),
                     new FileTextLoader(docFileInfo.FilePath, defaultEncoding),
                     docFileInfo.FilePath,
@@ -673,10 +677,14 @@ private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectF
             var additonalDocs = new List<DocumentInfo>();
             foreach (var docFileInfo in projectFileInfo.AdditionalDocuments)
             {
+                string name;
+                ImmutableArray<string> folders;
+                GetDocumentNameAndFolders(docFileInfo.LogicalPath, out name, out folders);
+
                 additonalDocs.Add(DocumentInfo.Create(
                     DocumentId.CreateNewId(projectId, debugName: docFileInfo.FilePath),
-                    Path.GetFileName(docFileInfo.LogicalPath),
-                    GetDocumentFolders(docFileInfo.LogicalPath),
+                    name,
+                    folders,
                     SourceCodeKind.Regular,
                     new FileTextLoader(docFileInfo.FilePath, defaultEncoding),
                     docFileInfo.FilePath,
@@ -709,7 +717,7 @@ private async Task<ProjectId> LoadProjectAsync(string projectFilePath, IProjectF
                 ProjectInfo.Create(
                     projectId,
                     version,
-                    name,
+                    projectName,
                     assemblyName,
                     loader.Language,
                     projectFilePath,
@@ -746,18 +754,29 @@ private static Encoding GetDefaultEncoding(int codePage)
             }
         }
 
-        private static readonly char[] s_directorySplitChars = new char[] { Path.DirectorySeparatorChar };
+        private static readonly char[] s_directorySplitChars = new char[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar };
 
-        private static ImmutableArray<string> GetDocumentFolders(string logicalPath)
+        private static void GetDocumentNameAndFolders(string logicalPath, out string name, out ImmutableArray<string> folders)
         {
-            var logicalDirectory = Path.GetDirectoryName(logicalPath);
+            var pathNames = logicalPath.Split(s_directorySplitChars, StringSplitOptions.RemoveEmptyEntries);
+            if (pathNames.Length > 0)
+            {
+                if (pathNames.Length > 1)
+                {
+                    folders = pathNames.Take(pathNames.Length - 1).ToImmutableArray();
+                }
+                else
+                {
+                    folders = ImmutableArray.Create<string>();
+                }
 
-            if (!string.IsNullOrEmpty(logicalDirectory))
+                name = pathNames[pathNames.Length - 1];
+            }
+            else
             {
-                return logicalDirectory.Split(s_directorySplitChars, StringSplitOptions.None).ToImmutableArray();
+                name = logicalPath;
+                folders = ImmutableArray.Create<string>();
             }
-
-            return ImmutableArray.Create<string>();
         }
 
         private void CheckDocuments(IEnumerable<DocumentFileInfo> docs, string projectFilePath, ProjectId projectId)

src/Workspaces/CoreTest/ServicesTest.csproj

@@ -311,6 +311,11 @@
   <ItemGroup>
     <EmbeddedResource Include="TestFiles\VisualBasicProject_VisualBasicProject_WithoutVBTargetsImported.vbproj" />
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="TestFiles\CSharpProject_CSharpProject_BadLink.csproj">
+      <SubType>Designer</SubType>
+    </EmbeddedResource>
+  </ItemGroup>
   <ImportGroup Label="Targets">
     <Import Project="..\..\Tools\Microsoft.CodeAnalysis.Toolset.Open\Targets\VSL.Imports.targets" />
     <Import Project="..\..\..\build\VSL.Imports.Closed.targets" />

src/Workspaces/CoreTest/TestFiles/CSharpProject_CSharpProject_BadLink.csproj

+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c)  Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information. -->
+<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProductVersion>8.0.30703</ProductVersion>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectGuid>{686DD036-86AA-443E-8A10-DDB43266A8C4}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>CSharpProject</RootNamespace>
+    <AssemblyName>CSharpProject</AssemblyName>
+    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AssemblyOriginatorKeyFile>snKey.snk</AssemblyOriginatorKeyFile>
+    <MyProperty>xyz</MyProperty>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+  </ItemGroup>
+  <ItemGroup>
+    <MyNode Include="CSharpClass.cs" />
+    <MyNode Include="Properties\AssemblyInfo.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="@(MyNode)">
+      <Link>$([MSBuild]::MakeRelative($(MyProperty), %(Identity))</Link>
+    </Compile>
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

src/Workspaces/CoreTest/WorkspaceTests/MSBuildWorkspaceTests.cs

@@ -2607,5 +2607,18 @@ public void TestAddRemoveProjectReference()
                 Assert.Equal(true, projFileText.Contains(@"<ProjectReference Include=""..\CSharpProject\CSharpProject.csproj"">"));
             }
         }
+
+        [Fact, Trait(Traits.Feature, Traits.Features.Workspace)]
+        [WorkItem(1101040)]
+        public void TestOpenProject_BadLink()
+        {
+            CreateFiles(GetSimpleCSharpSolutionFiles()
+                .WithFile(@"CSharpProject\CSharpProject.csproj", GetResourceText(@"CSharpProject_CSharpProject_BadLink.csproj")));
+
+            var ws = MSBuildWorkspace.Create();
+            var proj = ws.OpenProjectAsync(GetSolutionFileName(@"CSharpProject\CSharpProject.csproj")).Result;
+            var docs = proj.Documents.ToList();
+            Assert.Equal(3, docs.Count);
+        }
     }
 }