Merge pull request #12308 from Pilchie/unload-with-open-documents

Unload with open documents

src/EditorFeatures/CSharpTest/Workspaces/WorkspaceTests.cs

@@ -365,10 +365,9 @@ public void TestRemoveProjectWithOpenedDocuments()
                 workspace.AddTestProject(project1);
                 workspace.OnDocumentOpened(document.Id, document.GetOpenTextContainer());
 
-                Assert.Throws<ArgumentException>(() => workspace.OnProjectRemoved(project1.Id));
-
-                workspace.OnDocumentClosed(document.Id);
                 workspace.OnProjectRemoved(project1.Id);
+                Assert.False(workspace.IsDocumentOpen(document.Id));
+                Assert.Empty(workspace.CurrentSolution.Projects);
             }
         }
 

src/VisualStudio/Core/Def/Implementation/ProjectSystem/MiscellaneousFilesWorkspace.cs

@@ -350,6 +350,8 @@ private void DetachFromDocument(uint docCookie, string moniker)
                 _hostProjects.Remove(hostProject.Id);
                 _docCookiesToHostProject.Remove(docCookie);
 
+                document.Dispose();
+
                 return;
             }
         }

src/VisualStudio/Core/Def/Implementation/ProjectSystem/VisualStudioWorkspaceImpl.cs

@@ -877,10 +877,11 @@ internal void UpdateDocumentContextIfContainsDocument(IVsHierarchy sharedHierarc
             // find that one, we can map back to the open buffer and set its active context to
             // the appropriate project.
 
+            // Note that if there is a single head project and it's in the process of being unloaded
+            // there might not be a host project.
             var hostProject = LinkedFileUtilities.GetContextHostProject(sharedHierarchy, ProjectTracker);
-            if (hostProject.Hierarchy == sharedHierarchy)
+            if (hostProject?.Hierarchy == sharedHierarchy)
             {
-                // How?
                 return;
             }
 

src/Workspaces/Core/Portable/Workspace/Workspace.cs

@@ -425,9 +425,12 @@ protected internal virtual void OnProjectRemoved(ProjectId projectId)
             }
         }
 
+        /// <summary>
+        /// Currently projects can always be removed, but this method still exists because it's protected and we don't
+        /// want to break people who may have derived from <see cref="Workspace"/> and either called it, or overridden it.
+        /// </summary>
         protected virtual void CheckProjectCanBeRemoved(ProjectId projectId)
         {
-            CheckProjectDoesNotContainOpenDocuments(projectId);
         }
 
         /// <summary>

src/Workspaces/Core/Portable/Workspace/Workspace_Editor.cs

@@ -75,7 +75,9 @@ private void ClearOpenDocuments(ProjectId projectId)
 
             if (openDocs != null)
             {
-                foreach (var docId in openDocs)
+                // ClearOpenDocument will remove the document from the original set.
+                var copyOfOpenDocs = openDocs.ToList();
+                foreach (var docId in copyOfOpenDocs)
                 {
                     this.ClearOpenDocument(docId);
                 }