diff --git a/languages/clang/duchain/parsesession.cpp b/languages/clang/duchain/parsesession.cpp
index a8ab3fd8a1..c6f5df75f1 100644
--- a/languages/clang/duchain/parsesession.cpp
+++ b/languages/clang/duchain/parsesession.cpp
@@ -1,348 +1,352 @@
 /*
     This file is part of KDevelop
 
     Copyright 2013 Olivier de Gaalon <olivier.jg@gmail.com>
     Copyright 2013 Milian Wolff <mail@milianw.de>
     Copyright 2013 Kevin Funk <kfunk@kde.org>
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Library General Public License for more details.
 
     You should have received a copy of the GNU Library General Public License
     along with this library; see the file COPYING.LIB.  If not, write to
     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA 02110-1301, USA.
 */
 
 #include "parsesession.h"
 #include "clangproblem.h"
 #include "clangdiagnosticevaluator.h"
 #include "todoextractor.h"
 #include "clanghelpers.h"
 #include "clangindex.h"
 #include "clangparsingenvironment.h"
 #include "util/clangdebug.h"
 #include "util/clangtypes.h"
 #include "util/clangutils.h"
 
 #include <language/duchain/duchainlock.h>
 #include <language/duchain/duchain.h>
 
 #include <QDir>
 #include <QFileInfo>
 #include <QMimeDatabase>
 #include <QMimeType>
 
 #include <algorithm>
 
 using namespace KDevelop;
 
 namespace {
 
 QVector<QByteArray> argsForSession(const QString& path, ParseSessionData::Options options, const ParserSettings& parserSettings)
 {
     QMimeDatabase db;
     if(db.mimeTypeForFile(path).name() == QStringLiteral("text/x-objcsrc")) {
         return {QByteArrayLiteral("-xobjective-c++")};
     }
 
     if (parserSettings.parserOptions.isEmpty()) {
         // The parserOptions can be empty for some unit tests that use ParseSession directly
         auto defaultArguments = ClangSettingsManager::self()->parserSettings(nullptr).toClangAPI();
         Q_ASSERT(!defaultArguments.isEmpty());
         defaultArguments.append(QByteArrayLiteral("-nostdinc"));
         defaultArguments.append(QByteArrayLiteral("-nostdinc++"));
         defaultArguments.append(QByteArrayLiteral("-xc++"));
         return defaultArguments;
     }
 
     auto result = parserSettings.toClangAPI();
     result.append(QByteArrayLiteral("-nostdinc"));
     result.append(QByteArrayLiteral("-nostdinc++"));
 
     if (options & ParseSessionData::PrecompiledHeader) {
         result.append(parserSettings.isCpp() ? QByteArrayLiteral("-xc++-header") : QByteArrayLiteral("-xc-header"));
         return result;
     }
 
     result.append(parserSettings.isCpp() ? QByteArrayLiteral("-xc++") : QByteArrayLiteral("-xc"));
     return result;
 }
 
 void addIncludes(QVector<const char*>* args, QVector<QByteArray>* otherArgs,
                  const Path::List& includes, const char* cliSwitch)
 {
     foreach (const Path& url, includes) {
+        if (url.isEmpty()) {
+            continue;
+        }
+        
         QFileInfo info(url.toLocalFile());
         QByteArray path = url.toLocalFile().toUtf8();
 
         if (info.isFile()) {
             path.prepend("-include");
         } else {
             path.prepend(cliSwitch);
         }
         otherArgs->append(path);
         args->append(path.constData());
     }
 }
 
 QVector<CXUnsavedFile> toClangApi(const QVector<UnsavedFile>& unsavedFiles)
 {
     QVector<CXUnsavedFile> unsaved;
     unsaved.reserve(unsavedFiles.size());
     std::transform(unsavedFiles.begin(), unsavedFiles.end(),
                 std::back_inserter(unsaved),
                 [] (const UnsavedFile& file) { return file.toClangApi(); });
     return unsaved;
 }
 
 }
 
 ParseSessionData::ParseSessionData(const QVector<UnsavedFile>& unsavedFiles, ClangIndex* index,
                                    const ClangParsingEnvironment& environment, Options options)
     : m_file(nullptr)
     , m_unit(nullptr)
 {
     unsigned int flags = CXTranslationUnit_CXXChainedPCH
         | CXTranslationUnit_DetailedPreprocessingRecord;
     if (options.testFlag(SkipFunctionBodies)) {
         flags |= CXTranslationUnit_SkipFunctionBodies;
     }
     if (options.testFlag(PrecompiledHeader)) {
         flags |= CXTranslationUnit_ForSerialization;
     } else {
         flags |= CXTranslationUnit_CacheCompletionResults
               |  CXTranslationUnit_PrecompiledPreamble
               |  CXTranslationUnit_Incomplete;
     }
 
     const auto tuUrl = environment.translationUnitUrl();
     Q_ASSERT(!tuUrl.isEmpty());
 
     const auto arguments = argsForSession(tuUrl.str(), options, environment.parserSettings());
     QVector<const char*> clangArguments;
 
     const auto& includes = environment.includes();
     const auto& pchInclude = environment.pchInclude();
 
     // uses QByteArray as smart-pointer for const char* ownership
     QVector<QByteArray> smartArgs;
     smartArgs.reserve(includes.system.size() + includes.project.size()
                       + pchInclude.isValid() + arguments.size() + 1);
     clangArguments.reserve(smartArgs.size());
 
     std::transform(arguments.constBegin(), arguments.constEnd(),
                    std::back_inserter(clangArguments),
                    [] (const QByteArray &argument) { return argument.constData(); });
 
     // NOTE: the PCH include must come before all other includes!
     if (pchInclude.isValid()) {
         clangArguments << "-include";
         QByteArray pchFile = pchInclude.toLocalFile().toUtf8();
         smartArgs << pchFile;
         clangArguments << pchFile.constData();
     }
     addIncludes(&clangArguments, &smartArgs, includes.system, "-isystem");
     addIncludes(&clangArguments, &smartArgs, includes.project, "-I");
 
     m_definesFile.open();
     QTextStream definesStream(&m_definesFile);
     Q_ASSERT(m_definesFile.isWritable());
     const auto& defines = environment.defines();
     for (auto it = defines.begin(); it != defines.end(); ++it) {
         definesStream << QStringLiteral("#define ") << it.key() << ' ' << it.value() << '\n';
     }
     definesStream.flush();
     smartArgs << m_definesFile.fileName().toUtf8();
     clangArguments << "-imacros" << smartArgs.last().constData();
 
     QVector<CXUnsavedFile> unsaved;
     //For PrecompiledHeader, we don't want unsaved contents (and contents.isEmpty())
     if (!options.testFlag(PrecompiledHeader)) {
         unsaved = toClangApi(unsavedFiles);
     }
 
     const CXErrorCode code = clang_parseTranslationUnit2(
         index->index(), tuUrl.byteArray().constData(),
         clangArguments.constData(), clangArguments.size(),
         unsaved.data(), unsaved.size(),
         flags,
         &m_unit
     );
     if (code != CXError_Success) {
         qWarning() << "clang_parseTranslationUnit2 return with error code" << code;
     }
 
     if (m_unit) {
         setUnit(m_unit);
         m_environment = environment;
 
         if (options.testFlag(PrecompiledHeader)) {
             clang_saveTranslationUnit(m_unit, (tuUrl.byteArray() + ".pch").constData(), CXSaveTranslationUnit_None);
         }
     } else {
         qWarning() << "Failed to parse translation unit:" << tuUrl;
     }
 }
 
 ParseSessionData::~ParseSessionData()
 {
     clang_disposeTranslationUnit(m_unit);
 }
 
 void ParseSessionData::setUnit(CXTranslationUnit unit)
 {
     Q_ASSERT(!m_unit || unit == m_unit);
 
     m_unit = unit;
     const ClangString unitFile(clang_getTranslationUnitSpelling(unit));
     m_file = clang_getFile(m_unit, unitFile.c_str());
 }
 
 ClangParsingEnvironment ParseSessionData::environment() const
 {
     return m_environment;
 }
 
 ParseSession::ParseSession(const ParseSessionData::Ptr& data)
     : d(data)
 {
     if (d) {
         ENSURE_CHAIN_NOT_LOCKED
         d->m_mutex.lock();
     }
 }
 
 ParseSession::~ParseSession()
 {
     if (d) {
         d->m_mutex.unlock();
     }
 }
 
 void ParseSession::setData(const ParseSessionData::Ptr& data)
 {
     if (data == d) {
         return;
     }
 
     if (d) {
         d->m_mutex.unlock();
     }
 
     d = data;
 
     if (d) {
         ENSURE_CHAIN_NOT_LOCKED
         d->m_mutex.lock();
     }
 }
 
 ParseSessionData::Ptr ParseSession::data() const
 {
     return d;
 }
 
 IndexedString ParseSession::languageString()
 {
     static const IndexedString lang("Clang");
     return lang;
 }
 
 QList<ProblemPointer> ParseSession::problemsForFile(CXFile file) const
 {
     if (!d) {
         return {};
     }
 
     QList<ProblemPointer> problems;
 
     // extra clang diagnostics
     const uint numDiagnostics = clang_getNumDiagnostics(d->m_unit);
     problems.reserve(numDiagnostics);
     for (uint i = 0; i < numDiagnostics; ++i) {
         auto diagnostic = clang_getDiagnostic(d->m_unit, i);
 
         CXSourceLocation location = clang_getDiagnosticLocation(diagnostic);
         CXFile diagnosticFile;
         clang_getFileLocation(location, &diagnosticFile, nullptr, nullptr, nullptr);
         if (diagnosticFile != file) {
             continue;
         }
 
         ProblemPointer problem(ClangDiagnosticEvaluator::createProblem(diagnostic, d->m_unit));
         problems << problem;
 
         clang_disposeDiagnostic(diagnostic);
     }
 
     // other problem sources
 
     TodoExtractor extractor(unit(), file);
     problems << extractor.problems();
 
 #if CINDEX_VERSION_MINOR > 30
     // note that the below warning is triggered on every reparse when there is a precompiled preamble
     // see also TestDUChain::testReparseIncludeGuard
     const QString path = QDir(ClangString(clang_getFileName(file)).toString()).canonicalPath();
     const IndexedString indexedPath(path);
     if (ClangHelpers::isHeader(path) && !clang_isFileMultipleIncludeGuarded(unit(), file)
         && !clang_Location_isInSystemHeader(clang_getLocationForOffset(d->m_unit, file, 0)))
     {
         ProblemPointer problem(new Problem);
         problem->setSeverity(IProblem::Warning);
         problem->setDescription(i18n("Header is not guarded against multiple inclusions"));
         problem->setExplanation(i18n("The given header is not guarded against multiple inclusions, "
             "either with the conventional #ifndef/#define/#endif macro guards or with #pragma once."));
         problem->setFinalLocation({indexedPath, KTextEditor::Range()});
         problem->setSource(IProblem::Preprocessor);
         problems << problem;
         // TODO: Easy to add an assistant here that adds the guards -- any takers?
     }
 #endif
 
     return problems;
 }
 
 CXTranslationUnit ParseSession::unit() const
 {
     return d ? d->m_unit : nullptr;
 }
 
 CXFile ParseSession::file(const QByteArray& path) const
 {
     return clang_getFile(unit(), path.constData());
 }
 
 CXFile ParseSession::mainFile() const
 {
     return d ? d->m_file : nullptr;
 }
 
 bool ParseSession::reparse(const QVector<UnsavedFile>& unsavedFiles, const ClangParsingEnvironment& environment)
 {
     if (!d || environment != d->m_environment) {
         return false;
     }
 
     auto unsaved = toClangApi(unsavedFiles);
 
     if (clang_reparseTranslationUnit(d->m_unit, unsaved.size(), unsaved.data(), clang_defaultReparseOptions(d->m_unit)) == 0) {
         d->setUnit(d->m_unit);
         return true;
     } else {
         return false;
     }
 }
 
 ClangParsingEnvironment ParseSession::environment() const
 {
     return d->m_environment;
 }