C++: Fix 'already seen files' when indexing

Resetting the environment (after each *.cpp file) did not clear the
already seen files (m_included). Because of that the succeeding header
files were not parsed correctly - the environments of the mistakenly
already seen header files were not merged in.

Note that this change slow downs the parsing/indexing of files to its
original speed, as it was before the problematic commit (and it is in
2.7):

    commit 82e347095c
    C++: Untangle include file resolving from loading.

Task-number: QTCREATORBUG-9205
Change-Id: Iea57b7c59ea04a3c8843fd1291f4c375382958fc
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/cpptools/cppmodelmanager_test.cpp

@@ -74,6 +74,12 @@ public:
         return testDataDir(QLatin1String("sources")) + fileName;
     }
 
+    /// File from the test data directory (top leve)
+    QString file(const QString &fileName) const
+    {
+        return testDataDir(QString()) + fileName;
+    }
+
 private:
     QString testDataDir(const QString& subdir, bool cleaned = true) const
     {
@@ -166,7 +172,7 @@ void CppToolsPlugin::test_modelmanager_framework_headers()
 }
 
 /// QTCREATORBUG-9056
-void CppToolsPlugin::test_modelmanager_refresh()
+void CppToolsPlugin::test_modelmanager_refresh_1()
 {
     ModelManagerTestHelper helper;
     CppModelManager *mm = CppModelManager::instance();
@@ -178,7 +184,7 @@ void CppToolsPlugin::test_modelmanager_refresh()
     const QString testHeader(testDataDir.fileFromSourcesDir(
         QLatin1String("test_modelmanager_refresh.h")));
 
-    Project *project = helper.createProject(QLatin1String("test_modelmanager_refresh"));
+    Project *project = helper.createProject(QLatin1String("test_modelmanager_refresh_1"));
     ProjectInfo pi = mm->projectInfo(project);
     QCOMPARE(pi.project().data(), project);
 
@@ -216,3 +222,59 @@ void CppToolsPlugin::test_modelmanager_refresh()
     QVERIFY(snapshot.contains(testHeader));
     QVERIFY(snapshot.contains(testCpp));
 }
+
+/// QTCREATORBUG-9205
+void CppToolsPlugin::test_modelmanager_refresh_2()
+{
+    ModelManagerTestHelper helper;
+    CppModelManager *mm = CppModelManager::instance();
+
+    const TestDataDirectory testDataDir(QLatin1String("testdata_refresh"));
+
+    const QString testHeader1(testDataDir.file(QLatin1String("defines.h")));
+    const QString testHeader2(testDataDir.file(QLatin1String("header.h")));
+    const QString testCpp(testDataDir.file(QLatin1String("source.cpp")));
+
+    Project *project = helper.createProject(QLatin1String("test_modelmanager_refresh_2"));
+    ProjectInfo pi = mm->projectInfo(project);
+    QCOMPARE(pi.project().data(), project);
+
+    ProjectPart::Ptr part(new ProjectPart);
+    pi.appendProjectPart(part);
+    part->cxxVersion = ProjectPart::CXX98;
+    part->qtVersion = ProjectPart::Qt5;
+    part->files.append(ProjectFile(testHeader1, ProjectFile::CXXHeader));
+    part->files.append(ProjectFile(testHeader2, ProjectFile::CXXHeader));
+    part->files.append(ProjectFile(testCpp, ProjectFile::CXXSource));
+
+    mm->updateProjectInfo(pi);
+
+    CPlusPlus::Snapshot snapshot;
+    QStringList refreshedFiles;
+    CPlusPlus::Document::Ptr document;
+
+    for (int i = 0; i < 2; ++i) {
+        mm->updateSourceFiles(QStringList() << testHeader1 << testHeader2 << testCpp);
+        refreshedFiles = helper.waitForRefreshedSourceFiles();
+
+        QCOMPARE(refreshedFiles.size(), 3);
+        QVERIFY(refreshedFiles.contains(testHeader1));
+        QVERIFY(refreshedFiles.contains(testHeader2));
+        QVERIFY(refreshedFiles.contains(testCpp));
+
+        snapshot = mm->snapshot();
+        QVERIFY(snapshot.contains(testHeader1));
+        QVERIFY(snapshot.contains(testHeader2));
+        QVERIFY(snapshot.contains(testCpp));
+
+        // No diagnostic messages expected
+        document = snapshot.document(testHeader1);
+        QVERIFY(document->diagnosticMessages().isEmpty());
+
+        document = snapshot.document(testHeader2);
+        QVERIFY(document->diagnosticMessages().isEmpty());
+
+        document = snapshot.document(testCpp);
+        QVERIFY(document->diagnosticMessages().isEmpty());
+    }
+}

src/plugins/cpptools/cpppreprocessor.cpp

@@ -138,6 +138,7 @@ void CppPreprocessor::resetEnvironment()
 {
     m_env.reset();
     m_processed.clear();
+    m_included.clear();
 }
 
 void CppPreprocessor::getFileContents(const QString &absoluteFilePath,

src/plugins/cpptools/cpptoolsplugin.h

@@ -141,7 +141,8 @@ private slots:
 
     void test_modelmanager_paths();
     void test_modelmanager_framework_headers();
-    void test_modelmanager_refresh();
+    void test_modelmanager_refresh_1();
+    void test_modelmanager_refresh_2();
 
 private:
     void test_completion();

tests/cppmodelmanager/testdata_refresh/defines.h

@@ -0,0 +1,31 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+
+#define FORWARD_DECLARE_CLASS(name) class name;

tests/cppmodelmanager/testdata_refresh/header.h

@@ -0,0 +1,33 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+
+#include "defines.h"
+
+FORWARD_DECLARE_CLASS(QAction)

tests/cppmodelmanager/testdata_refresh/source.cpp

@@ -0,0 +1,33 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+
+#include "defines.h"
+
+FORWARD_DECLARE_CLASS(QAction)