Fix rename-project crashing bug.

Author: Hosch250

RetailCoder.VBE/UI/Command/AddTestModuleCommand.cs

@@ -25,15 +25,7 @@ public AddTestModuleCommand(VBE vbe, RubberduckParserState state, NewUnitTestMod
 
         public override bool CanExecute(object parameter)
         {
-            var app = _vbe.HostApplication();
-            if (app == null || _state.Status != ParserState.Ready)
-            {
-                return false;
-            }
-            
-            // Outlook requires test methods to be located in [ThisOutlookSession] class.
-            //return app.ApplicationName != "Outlook";
-            return true;
+            return _vbe.HostSupportsUnitTests();
         }
 
         public override void Execute(object parameter)

Rubberduck.Parsing/VBA/RubberduckParserState.cs

@@ -158,7 +158,7 @@ public void RemoveProject(string projectId)
 
         public void RemoveProject(VBProject project)
         {
-            RemoveProject(QualifiedModuleName.GetProjectId(project));
+            RemoveProject(project.HelpFile);
             ClearStateCache(project);
         }
 
@@ -584,6 +584,12 @@ public void ClearStateCache(VBProject project, bool notifyStateChanged = false)
                         // until Hell freezes over?
                     }
                 }
+
+                ModuleState state;
+                if (_moduleStates.TryRemove(new QualifiedModuleName(project), out state))
+                {
+                    state.Dispose();
+                }
             }
             catch (COMException)
             {
@@ -690,6 +696,10 @@ public bool RemoveRenamedComponent(VBComponent component, string oldComponentNam
                 OnStateChanged(ParserState.ResolvedDeclarations);   // trigger test explorer and code explorer updates
                 OnStateChanged(ParserState.Ready);   // trigger find all references &c. updates
             }
+
+            _projects.Remove(match.ProjectId);
+            _projects.Add(match.ProjectId, component.Collection.Parent);
+
             return success;
         }
 

Rubberduck.VBEEditor/Extensions/VbeExtensions.cs

@@ -78,7 +78,7 @@ public static IHostApplication HostApplication(this VBE vbe)
                             return new CorelDRAWApp();
                     }
                 }
-                return null;// new FallbackApp(vbe);
+                return null;
             }
 
             foreach (var reference in vbe.ActiveVBProject.References.Cast<Reference>()
@@ -109,7 +109,61 @@ public static IHostApplication HostApplication(this VBE vbe)
                 }
             }
 
-            return null; //new FallbackApp(vbe);
+            return null;
+        }
+
+        /// <summary> Returns whether the host supports unit tests.</summary>
+        public static bool HostSupportsUnitTests(this VBE vbe)
+        {
+            if (vbe.ActiveVBProject == null)
+            {
+                const int ctlViewHost = 106;
+
+                var hostAppControl = vbe.CommandBars.FindControl(MsoControlType.msoControlButton, ctlViewHost);
+
+                if (hostAppControl == null)
+                {
+                    return false;
+                }
+
+                switch (hostAppControl.Caption)
+                {
+                    case "Microsoft Excel":
+                    case "Microsoft Access":
+                    case "Microsoft Word":
+                    case "Microsoft PowerPoint":
+                    case "Microsoft Outlook":
+                    case "Microsoft Project":
+                    case "Microsoft Publisher":
+                    case "Microsoft Visio":
+                    case "AutoCAD":
+                    case "CorelDRAW":
+                        return true;
+                    default:
+                        return false;
+                }
+            }
+
+            foreach (var reference in vbe.ActiveVBProject.References.Cast<Reference>()
+                .Where(reference => (reference.BuiltIn && reference.Name != "VBA") || (reference.Name == "AutoCAD")))
+            {
+                switch (reference.Name)
+                {
+                    case "Excel":
+                    case "Access":
+                    case "Word":
+                    case "PowerPoint":
+                    case "Outlook":
+                    case "MSProject":
+                    case "Publisher":
+                    case "Visio":
+                    case "AutoCAD":
+                    case "CorelDRAW":
+                        return true;
+                }
+            }
+
+            return false;
         }
     }
 }

Rubberduck.VBEEditor/QualifiedModuleName.cs

@@ -108,9 +108,13 @@ public static string GetProjectId(VBProject project)
             {
                 return string.Empty;
             }
-            return string.IsNullOrEmpty(project.HelpFile) 
-                ? project.GetHashCode().ToString() 
-                : project.HelpFile;
+
+            if (string.IsNullOrEmpty(project.HelpFile))
+            {
+                project.HelpFile = project.GetHashCode().ToString();
+            }
+
+            return project.HelpFile;
         }
 
         public static string GetProjectId(Reference reference)