CppTools: Use fallback project part if project is closed

...instead of sticking to the old one.

If a project is closed, the editor should reflect that. It also simplifies the code.

Change-Id: I9b8a94513d3b06a238cfc4ee60c11c0d0da3d93f
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/cpptools/baseeditordocumentparser.cpp

@@ -122,7 +122,7 @@ BaseEditorDocumentParser::Ptr BaseEditorDocumentParser::get(const QString &fileP
 ProjectPartInfo BaseEditorDocumentParser::determineProjectPart(
         const QString &filePath,
         const Configuration &config,
-        const State &state,
+        const ProjectPartInfo &currentProjectPartInfo,
         const ProjectExplorer::Project *activeProject,
         Language languagePreference,
         bool hasActiveProjectChanged)
@@ -143,9 +143,8 @@ ProjectPartInfo BaseEditorDocumentParser::determineProjectPart(
 
     const ProjectPartInfo chooserResult
             = chooser.choose(filePath,
-                             state.projectPartInfo.projectPart,
+                             currentProjectPartInfo,
                              config.manuallySetProjectPart,
-                             config.stickToPreviousProjectPart,
                              activeProject,
                              languagePreference,
                              hasActiveProjectChanged);