QmakeProjectManager: Fix crash on reparsing

After a re-parse, the existing IDocuments need to be updated with the
new QmakePriFile object, as the old one may no longer be valid and thus
cause a crash on the next re-parse.
Amends f3bd07efd1.

Fixes: QTCREATORBUG-24683
Change-Id: Ib03d3005cb7831f1e05cb116aa3cdfe6cf5e72ad
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/projectexplorer/project.cpp

@@ -357,7 +357,8 @@ void Project::setNeedsInitialExpansion(bool needsExpansion)
 }
 
 void Project::setExtraProjectFiles(const QSet<Utils::FilePath> &projectDocumentPaths,
-                                   const DocGenerator docGenerator)
+                                   const DocGenerator &docGenerator,
+                                   const DocUpdater &docUpdater)
 {
     QSet<Utils::FilePath> uniqueNewFiles = projectDocumentPaths;
     uniqueNewFiles.remove(projectFilePath()); // Make sure to never add the main project file!
@@ -371,6 +372,10 @@ void Project::setExtraProjectFiles(const QSet<Utils::FilePath> &projectDocumentP
     Utils::erase(d->m_extraProjectDocuments, [&toRemove](const std::unique_ptr<Core::IDocument> &d) {
         return toRemove.contains(d->filePath());
     });
+    if (docUpdater) {
+        for (const auto &doc : qAsConst(d->m_extraProjectDocuments))
+            docUpdater(doc.get());
+    }
     for (const Utils::FilePath &p : toAdd) {
         if (docGenerator) {
             std::unique_ptr<Core::IDocument> doc = docGenerator(p);

src/plugins/projectexplorer/project.h

@@ -165,8 +165,10 @@ public:
     // Set project files that will be watched and by default trigger the same callback
     // as the main project file.
     using DocGenerator = std::function<std::unique_ptr<Core::IDocument>(const Utils::FilePath &)>;
+    using DocUpdater = std::function<void(Core::IDocument *)>;
     void setExtraProjectFiles(const QSet<Utils::FilePath> &projectDocumentPaths,
-                              const DocGenerator docGenerator = {});
+                              const DocGenerator &docGenerator = {},
+                              const DocUpdater &docUpdater = {});
 
     void setDisplayName(const QString &name);
     void setProjectLanguage(Utils::Id id, bool enabled);

src/plugins/qmakeprojectmanager/qmakeproject.cpp

@@ -127,6 +127,8 @@ public:
         return true;
     }
 
+    void setPriFile(QmakePriFile *priFile) { m_priFile = priFile; }
+
 private:
     QmakePriFile *m_priFile;
 };
@@ -305,15 +307,24 @@ void QmakeBuildSystem::updateDocuments()
         projectDocuments.insert(n->filePath());
 
     });
-    project()->setExtraProjectFiles(projectDocuments, [p = project()](const FilePath &fp)
+    const auto priFileForPath = [p = project()](const FilePath &fp) -> QmakePriFile * {
-            -> std::unique_ptr<Core::IDocument> {
         const Node * const n = p->nodeForFilePath(fp, [](const Node *n) {
             return dynamic_cast<const QmakePriFileNode *>(n); });
-        QTC_ASSERT(n, return std::make_unique<Core::IDocument>());
+        QTC_ASSERT(n, return nullptr);
-        QmakePriFile * const priFile = static_cast<const QmakePriFileNode *>(n)->priFile();
+        return static_cast<const QmakePriFileNode *>(n)->priFile();
+    };
+    const auto docGenerator = [&](const FilePath &fp)
+            -> std::unique_ptr<Core::IDocument> {
+        QmakePriFile * const priFile = priFileForPath(fp);
         QTC_ASSERT(priFile, return std::make_unique<Core::IDocument>());
         return std::make_unique<QmakePriFileDocument>(priFile, fp);
-    });
+    };
+    const auto docUpdater = [&](Core::IDocument *doc) {
+        QmakePriFile * const priFile = priFileForPath(doc->filePath());
+        QTC_ASSERT(priFile, return);
+        static_cast<QmakePriFileDocument *>(doc)->setPriFile(priFile);
+    };
+    project()->setExtraProjectFiles(projectDocuments, docGenerator, docUpdater);
 }
 
 void QmakeBuildSystem::updateCppCodeModel()