QmakeProjectManager: Fix possible crash on project document reload

... while a parse is going on.

Fixes: QTCREATORBUG-25137
Change-Id: I02a914332ef120caee044139581e1901b4537bff
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/projectexplorer/project.cpp

@@ -388,6 +388,25 @@ void Project::setExtraProjectFiles(const QSet<Utils::FilePath> &projectDocumentP
     }
 }
 
+void Project::updateExtraProjectFiles(const QSet<Utils::FilePath> &projectDocumentPaths,
+                                      const DocUpdater &docUpdater)
+{
+    for (const Utils::FilePath &fp : projectDocumentPaths) {
+        for (const auto &doc : d->m_extraProjectDocuments) {
+            if (doc->filePath() == fp) {
+                docUpdater(doc.get());
+                break;
+            }
+        }
+    }
+}
+
+void Project::updateExtraProjectFiles(const DocUpdater &docUpdater)
+{
+    for (const auto &doc : qAsConst(d->m_extraProjectDocuments))
+        docUpdater(doc.get());
+}
+
 Target *Project::target(Utils::Id id) const
 {
     return Utils::findOrDefault(d->m_targets, Utils::equal(&Target::id, id));

src/plugins/projectexplorer/project.h

@@ -169,6 +169,9 @@ public:
     void setExtraProjectFiles(const QSet<Utils::FilePath> &projectDocumentPaths,
                               const DocGenerator &docGenerator = {},
                               const DocUpdater &docUpdater = {});
+    void updateExtraProjectFiles(const QSet<Utils::FilePath> &projectDocumentPaths,
+                                 const DocUpdater &docUpdater);
+    void updateExtraProjectFiles(const DocUpdater &docUpdater);
 
     void setDisplayName(const QString &name);
     void setProjectLanguage(Utils::Id id, bool enabled);

src/plugins/qmakeprojectmanager/qmakeproject.cpp

@@ -122,7 +122,8 @@ public:
         Q_UNUSED(errorString)
         Q_UNUSED(flag)
         Q_UNUSED(type)
-        m_priFile->scheduleUpdate();
+        if (m_priFile)
+            m_priFile->scheduleUpdate();
         return true;
     }
 
@@ -692,7 +693,26 @@ void QmakeBuildSystem::asyncUpdate()
         return;
     }
 
+    // Make sure we ignore requests for re-evaluation for files whose QmakePriFile objects
+    // will get deleted during the parse.
+    const auto docUpdater = [](Core::IDocument *doc) {
+        static_cast<QmakePriFileDocument *>(doc)->setPriFile(nullptr);
+    };
+    if (m_asyncUpdateState != AsyncFullUpdatePending) {
+        QSet<FilePath> projectFilePaths;
+        for (QmakeProFile * const file : qAsConst(m_partialEvaluate)) {
+            QVector<QmakePriFile *> priFiles = file->children();
+            for (int i = 0; i < priFiles.count(); ++i) {
+                const QmakePriFile * const priFile = priFiles.at(i);
+                projectFilePaths << priFile->filePath();
+                priFiles << priFile->children();
+            }
+        }
+        project()->updateExtraProjectFiles(projectFilePaths, docUpdater);
+    }
+
     if (m_asyncUpdateState == AsyncFullUpdatePending) {
+        project()->updateExtraProjectFiles(docUpdater);
         rootProFile()->asyncUpdate();
     } else {
         foreach (QmakeProFile *file, m_partialEvaluate)