diff --git a/src/plugins/diffeditor/diffeditorcontroller.cpp b/src/plugins/diffeditor/diffeditorcontroller.cpp
index 0c0c51dbd3e..17048c23d78 100644
--- a/src/plugins/diffeditor/diffeditorcontroller.cpp
+++ b/src/plugins/diffeditor/diffeditorcontroller.cpp
@@ -35,6 +35,8 @@
 
 #include <QStringList>
 
+using namespace Utils;
+
 namespace DiffEditor {
 
 DiffEditorController::DiffEditorController(Core::IDocument *document) :
@@ -50,12 +52,12 @@ bool DiffEditorController::isReloading() const
     return m_isReloading;
 }
 
-QString DiffEditorController::baseDirectory() const
+FilePath DiffEditorController::baseDirectory() const
 {
     return m_document->baseDirectory();
 }
 
-void DiffEditorController::setBaseDirectory(const QString &directory)
+void DiffEditorController::setBaseDirectory(const FilePath &directory)
 {
     m_document->setBaseDirectory(directory);
 }
@@ -94,7 +96,7 @@ DiffEditorController *DiffEditorController::controller(Core::IDocument *document
 }
 
 void DiffEditorController::setDiffFiles(const QList<FileData> &diffFileList,
-                                        const QString &workingDirectory,
+                                        const FilePath &workingDirectory,
                                         const QString &startupFile)
 {
     m_document->setDiffFiles(diffFileList, workingDirectory, startupFile);
diff --git a/src/plugins/diffeditor/diffeditorcontroller.h b/src/plugins/diffeditor/diffeditorcontroller.h
index b97a0f56658..bb3100060ef 100644
--- a/src/plugins/diffeditor/diffeditorcontroller.h
+++ b/src/plugins/diffeditor/diffeditorcontroller.h
@@ -49,8 +49,8 @@ public:
     void requestReload();
     bool isReloading() const;
 
-    QString baseDirectory() const;
-    void setBaseDirectory(const QString &directory);
+    Utils::FilePath baseDirectory() const;
+    void setBaseDirectory(const Utils::FilePath &directory);
     int contextLineCount() const;
     bool ignoreWhitespace() const;
 
@@ -84,7 +84,7 @@ protected:
     void reloadFinished(bool success);
 
     void setDiffFiles(const QList<FileData> &diffFileList,
-                      const QString &baseDirectory = QString(),
+                      const Utils::FilePath &baseDirectory = {},
                       const QString &startupFile = QString());
     void setDescription(const QString &description);
     QString description() const;
diff --git a/src/plugins/diffeditor/diffeditordocument.cpp b/src/plugins/diffeditor/diffeditordocument.cpp
index d4a8f7851da..362b867199b 100644
--- a/src/plugins/diffeditor/diffeditordocument.cpp
+++ b/src/plugins/diffeditor/diffeditordocument.cpp
@@ -171,7 +171,7 @@ QString DiffEditorDocument::makePatch(int fileIndex, int chunkIndex,
                                 lastChunk && fileData.lastChunkAtTheEndOfFile);
 }
 
-void DiffEditorDocument::setDiffFiles(const QList<FileData> &data, const QString &directory,
+void DiffEditorDocument::setDiffFiles(const QList<FileData> &data, const FilePath &directory,
                                       const QString &startupFile)
 {
     m_diffFiles = data;
@@ -186,12 +186,12 @@ QList<FileData> DiffEditorDocument::diffFiles() const
     return m_diffFiles;
 }
 
-QString DiffEditorDocument::baseDirectory() const
+FilePath DiffEditorDocument::baseDirectory() const
 {
     return m_baseDirectory;
 }
 
-void DiffEditorDocument::setBaseDirectory(const QString &directory)
+void DiffEditorDocument::setBaseDirectory(const FilePath &directory)
 {
     m_baseDirectory = directory;
 }
@@ -256,7 +256,7 @@ bool DiffEditorDocument::setContents(const QByteArray &contents)
 QString DiffEditorDocument::fallbackSaveAsPath() const
 {
     if (!m_baseDirectory.isEmpty())
-        return m_baseDirectory;
+        return m_baseDirectory.toString();
     return QDir::homePath();
 }
 
@@ -265,7 +265,7 @@ bool DiffEditorDocument::isSaveAsAllowed() const
     return state() == LoadOK;
 }
 
-bool DiffEditorDocument::save(QString *errorString, const Utils::FilePath &filePath, bool autoSave)
+bool DiffEditorDocument::save(QString *errorString, const FilePath &filePath, bool autoSave)
 {
     Q_UNUSED(errorString)
     Q_UNUSED(autoSave)
@@ -330,7 +330,7 @@ Core::IDocument::OpenResult DiffEditorDocument::open(QString *errorString, const
         setTemporary(false);
         emit temporaryStateChanged();
         setFilePath(filePath.absoluteFilePath());
-        setDiffFiles(fileDataList, filePath.absoluteFilePath().toString());
+        setDiffFiles(fileDataList, filePath.absoluteFilePath());
     }
     endReload(ok);
     if (!ok && readResult == TextFileFormat::ReadEncodingError)
@@ -415,7 +415,7 @@ void DiffEditorDocument::beginReload()
     m_state = Reloading;
     emit changed();
     QSignalBlocker blocker(this);
-    setDiffFiles(QList<FileData>(), QString());
+    setDiffFiles(QList<FileData>(), {});
     setDescription(QString());
 }
 
diff --git a/src/plugins/diffeditor/diffeditordocument.h b/src/plugins/diffeditor/diffeditordocument.h
index a4dc866553a..3354b56080f 100644
--- a/src/plugins/diffeditor/diffeditordocument.h
+++ b/src/plugins/diffeditor/diffeditordocument.h
@@ -59,11 +59,11 @@ public:
                       bool revert, bool addPrefix = false,
                       const QString &overriddenFileName = QString()) const;
 
-    void setDiffFiles(const QList<FileData> &data, const QString &directory,
+    void setDiffFiles(const QList<FileData> &data, const Utils::FilePath &directory,
                       const QString &startupFile = QString());
     QList<FileData> diffFiles() const;
-    QString baseDirectory() const;
-    void setBaseDirectory(const QString &directory);
+    Utils::FilePath baseDirectory() const;
+    void setBaseDirectory(const Utils::FilePath &directory);
     QString startupFile() const;
 
     void setDescription(const QString &description);
@@ -103,7 +103,7 @@ private:
 
     DiffEditorController *m_controller = nullptr;
     QList<FileData> m_diffFiles;
-    QString m_baseDirectory;
+    Utils::FilePath m_baseDirectory;
     QString m_startupFile;
     QString m_description;
     int m_contextLineCount = 3;
diff --git a/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp b/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp
index ce995a32caf..09050b57d08 100644
--- a/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp
+++ b/src/plugins/diffeditor/diffeditorwidgetcontroller.cpp
@@ -159,12 +159,10 @@ void DiffEditorWidgetController::patch(bool revert, int fileIndex, int chunkInde
             ? fileData.rightFileInfo.patchBehaviour
             : fileData.leftFileInfo.patchBehaviour;
 
-    const QString workingDirectory = m_document->baseDirectory().isEmpty()
-            ? QFileInfo(fileName).absolutePath()
+    const FilePath workingDirectory = m_document->baseDirectory().isEmpty()
+            ? FilePath::fromString(fileName).absolutePath()
             : m_document->baseDirectory();
-    const Utils::FilePath absFilePath = Utils::FilePath::fromString(workingDirectory)
-                                            .pathAppended(QFileInfo(fileName).fileName())
-                                            .absoluteFilePath();
+    const FilePath absFilePath = workingDirectory.resolvePath(fileName).absoluteFilePath();
 
     if (patchBehaviour == DiffFileInfo::PatchFile) {
         const int strip = m_document->baseDirectory().isEmpty() ? -1 : 0;
@@ -176,7 +174,7 @@ void DiffEditorWidgetController::patch(bool revert, int fileIndex, int chunkInde
 
         FileChangeBlocker fileChangeBlocker(absFilePath);
         if (PatchTool::runPatch(EditorManager::defaultTextCodec()->fromUnicode(patch),
-                                FilePath::fromString(workingDirectory), strip, revert))
+                                workingDirectory, strip, revert))
             m_document->reload();
     } else { // PatchEditor
         auto textDocument = qobject_cast<TextEditor::TextDocument *>(
@@ -217,11 +215,9 @@ void DiffEditorWidgetController::jumpToOriginalFile(const QString &fileName,
     if (!m_document)
         return;
 
-    const QDir dir(m_document->baseDirectory());
-    const QString absoluteFileName = dir.absoluteFilePath(fileName);
-    const QFileInfo fi(absoluteFileName);
-    if (fi.exists() && !fi.isDir())
-        EditorManager::openEditorAt(absoluteFileName, lineNumber, columnNumber);
+    const FilePath filePath = m_document->baseDirectory().resolvePath(fileName);
+    if (filePath.exists() && !filePath.isDir())
+        EditorManager::openEditorAt(filePath.toString(), lineNumber, columnNumber);
 }
 
 void DiffEditorWidgetController::setFontSettings(const FontSettings &fontSettings)
diff --git a/src/plugins/diffeditor/diffutils.h b/src/plugins/diffeditor/diffutils.h
index aa8d66ca43c..c2cfd7c9008 100644
--- a/src/plugins/diffeditor/diffutils.h
+++ b/src/plugins/diffeditor/diffutils.h
@@ -27,8 +27,10 @@
 
 #include "diffeditor_global.h"
 
-#include <QString>
+#include <utils/filepath.h>
+
 #include <QMap>
+#include <QString>
 
 QT_BEGIN_NAMESPACE
 class QFutureInterfaceBase;
diff --git a/src/plugins/git/gitclient.cpp b/src/plugins/git/gitclient.cpp
index 9f18a28324c..290c3603374 100644
--- a/src/plugins/git/gitclient.cpp
+++ b/src/plugins/git/gitclient.cpp
@@ -329,7 +329,7 @@ void GitBaseDiffEditorController::initialize()
         // we compare the current state of working tree to the HEAD of current branch
         // instead of showing unsupported combined diff format.
         GitClient::CommandInProgress commandInProgress =
-                m_instance->checkCommandInProgress(FilePath::fromString(workingDirectory()));
+                m_instance->checkCommandInProgress(workingDirectory());
         if (commandInProgress != GitClient::NoCommand)
             m_rightCommit = HEAD;
     }
@@ -341,11 +341,11 @@ void GitBaseDiffEditorController::updateBranchList()
     if (revision.isEmpty())
         return;
 
-    const QString workingDirectory = baseDirectory();
+    const FilePath workingDirectory = baseDirectory();
     VcsCommand *command = m_instance->vcsExec(
-                FilePath::fromString(workingDirectory),
+                workingDirectory,
                 {"branch", noColorOption, "-a", "--contains", revision}, nullptr,
-                false, 0, workingDirectory);
+                false, 0, workingDirectory.toString());
     connect(command, &VcsCommand::stdOutText, this, [this](const QString &text) {
         const QString remotePrefix = "remotes/";
         const QString localPrefix = "<Local>";
@@ -459,7 +459,7 @@ public:
         setReloader([this] {
             m_state = GettingDescription;
             const QStringList args = {"show", "-s", noColorOption, showFormatC, m_id};
-            runCommand({args}, m_instance->encoding(FilePath::fromString(workingDirectory()), "i18n.commitEncoding"));
+            runCommand({args}, m_instance->encoding(workingDirectory(), "i18n.commitEncoding"));
             setStartupFile(VcsBase::source(this->document()));
         });
     }
@@ -476,7 +476,7 @@ void ShowController::processCommandOutput(const QString &output)
 {
     QTC_ASSERT(m_state != Idle, return);
     if (m_state == GettingDescription) {
-        setDescription(m_instance->extendedShowDescription(FilePath::fromString(workingDirectory()), output));
+        setDescription(m_instance->extendedShowDescription(workingDirectory(), output));
         // stage 2
         m_state = GettingDiff;
         const QStringList args = {"show", "--format=format:", // omit header, already generated
@@ -941,11 +941,11 @@ void GitClient::chunkActionsRequested(QMenu *menu, int fileIndex, int chunkIndex
 void GitClient::stage(DiffEditor::DiffEditorController *diffController,
                       const QString &patch, bool revert)
 {
-    Utils::TemporaryFile patchFile("git-patchfile");
+    TemporaryFile patchFile("git-patchfile");
     if (!patchFile.open())
         return;
 
-    const FilePath baseDir = FilePath::fromString(diffController->baseDirectory());
+    const FilePath baseDir = diffController->baseDirectory();
     QTextCodec *codec = EditorManager::defaultTextCodec();
     const QByteArray patchData = codec
             ? codec->fromUnicode(patch) : patch.toLocal8Bit();
@@ -986,7 +986,7 @@ void GitClient::requestReload(const QString &documentId, const QString &source,
     controller->setVcsBinary(settings().binaryPath.filePath());
     controller->setVcsTimeoutS(settings().timeout.value());
     controller->setProcessEnvironment(processEnvironment());
-    controller->setWorkingDirectory(workingDirectory.toString());
+    controller->setWorkingDirectory(workingDirectory);
     controller->initialize();
 
     connect(controller, &DiffEditorController::chunkActionsRequested,
diff --git a/src/plugins/mercurial/mercurialclient.cpp b/src/plugins/mercurial/mercurialclient.cpp
index 2f06a8a8247..b7093f4196f 100644
--- a/src/plugins/mercurial/mercurialclient.cpp
+++ b/src/plugins/mercurial/mercurialclient.cpp
@@ -355,20 +355,20 @@ void MercurialClient::diff(const FilePath &workingDir, const QStringList &files,
         const QString sourceFile = VcsBaseEditor::getSource(workingDir, fileName);
         const QString documentId = QString(Constants::MERCURIAL_PLUGIN)
                 + ".DiffRepo." + sourceFile;
-        requestReload(documentId, sourceFile, title, workingDir.toString(), {"diff"});
+        requestReload(documentId, sourceFile, title, workingDir, {"diff"});
     } else if (files.size() == 1) {
         fileName = files.at(0);
         const QString title = tr("Mercurial Diff \"%1\"").arg(fileName);
         const QString sourceFile = VcsBaseEditor::getSource(workingDir, fileName);
         const QString documentId = QString(Constants::MERCURIAL_PLUGIN)
                 + ".DiffFile." + sourceFile;
-        requestReload(documentId, sourceFile, title, workingDir.toString(), {"diff", fileName});
+        requestReload(documentId, sourceFile, title, workingDir, {"diff", fileName});
     } else {
         const QString title = tr("Mercurial Diff \"%1\"").arg(workingDir.toString());
         const QString sourceFile = VcsBaseEditor::getSource(workingDir, fileName);
         const QString documentId = QString(Constants::MERCURIAL_PLUGIN)
                 + ".DiffFile." + workingDir.toString();
-        requestReload(documentId, sourceFile, title, workingDir.toString(), QStringList{"diff"} + files);
+        requestReload(documentId, sourceFile, title, workingDir, QStringList{"diff"} + files);
     }
 }
 
@@ -455,7 +455,7 @@ MercurialClient::StatusItem MercurialClient::parseStatusLine(const QString &line
 }
 
 void MercurialClient::requestReload(const QString &documentId, const QString &source, const QString &title,
-                                    const QString &workingDirectory, const QStringList &args)
+                                    const FilePath &workingDirectory, const QStringList &args)
 {
     // Creating document might change the referenced source. Store a copy and use it.
     const QString sourceCopy = source;
diff --git a/src/plugins/mercurial/mercurialclient.h b/src/plugins/mercurial/mercurialclient.h
index 7a9bd3dabd0..579ca45c501 100644
--- a/src/plugins/mercurial/mercurialclient.h
+++ b/src/plugins/mercurial/mercurialclient.h
@@ -91,7 +91,7 @@ signals:
 
 private:
     void requestReload(const QString &documentId, const QString &source, const QString &title,
-                       const QString &workingDirectory,
+                       const Utils::FilePath &workingDirectory,
                        const QStringList &args);
     void parsePullOutput(const QString &output);
 };
diff --git a/src/plugins/subversion/subversionclient.cpp b/src/plugins/subversion/subversionclient.cpp
index cd6e6663e99..01c4eae407f 100644
--- a/src/plugins/subversion/subversionclient.cpp
+++ b/src/plugins/subversion/subversionclient.cpp
@@ -260,7 +260,7 @@ void SubversionDiffEditorController::processCommandOutput(const QString &output)
 SubversionDiffEditorController *SubversionClient::findOrCreateDiffEditor(const QString &documentId,
                                                          const QString &source,
                                                          const QString &title,
-                                                         const QString &workingDirectory)
+                                                         const FilePath &workingDirectory)
 {
     auto &settings = static_cast<SubversionSettings &>(this->settings());
     IDocument *document = DiffEditorController::findOrCreateDocument(documentId, title);
@@ -288,7 +288,7 @@ void SubversionClient::diff(const FilePath &workingDirectory, const QStringList
     const QString title = vcsEditorTitle(vcsCmdString, documentId);
 
     SubversionDiffEditorController *controller =
-            findOrCreateDiffEditor(documentId, workingDirectory.toString(), title, workingDirectory.toString());
+            findOrCreateDiffEditor(documentId, workingDirectory.toString(), title, workingDirectory);
     controller->setFilesList(files);
     controller->requestReload();
 }
@@ -319,7 +319,7 @@ void SubversionClient::describe(const FilePath &workingDirectory, int changeNumb
                                                         QString::number(changeNumber));
 
     SubversionDiffEditorController *controller =
-            findOrCreateDiffEditor(documentId, workingDirectory.toString(), title, workingDirectory.toString());
+            findOrCreateDiffEditor(documentId, workingDirectory.toString(), title, workingDirectory);
     controller->setChangeNumber(changeNumber);
     controller->requestReload();
 }
diff --git a/src/plugins/subversion/subversionclient.h b/src/plugins/subversion/subversionclient.h
index 036f314b152..f1c05b27c93 100644
--- a/src/plugins/subversion/subversionclient.h
+++ b/src/plugins/subversion/subversionclient.h
@@ -77,7 +77,7 @@ protected:
 
 private:
     SubversionDiffEditorController *findOrCreateDiffEditor(const QString &documentId, const QString &source,
-                                           const QString &title, const QString &workingDirectory);
+                                           const QString &title, const Utils::FilePath &workingDirectory);
 
     mutable Utils::FilePath m_svnVersionBinary;
     mutable QString m_svnVersion;
diff --git a/src/plugins/vcsbase/vcsbasediffeditorcontroller.cpp b/src/plugins/vcsbase/vcsbasediffeditorcontroller.cpp
index 81c9234b3ea..3448af8e16c 100644
--- a/src/plugins/vcsbase/vcsbasediffeditorcontroller.cpp
+++ b/src/plugins/vcsbase/vcsbasediffeditorcontroller.cpp
@@ -95,9 +95,9 @@ public:
     void commandFinished(bool success);
 
     VcsBaseDiffEditorController *q;
-    QString m_directory;
+    FilePath m_directory;
     Environment m_processEnvironment;
-    Utils::FilePath m_vcsBinary;
+    FilePath m_vcsBinary;
     int m_vscTimeoutS;
     QString m_startupFile;
     QString m_output;
@@ -241,7 +241,7 @@ void VcsBaseDiffEditorController::runCommand(const QList<QStringList> &args, uns
     // and "Waiting for data..." will be shown.
     d->cancelReload();
 
-    d->m_command = new VcsCommand(FilePath::fromString(workingDirectory()), d->m_processEnvironment);
+    d->m_command = new VcsCommand(workingDirectory(), d->m_processEnvironment);
     d->m_command->setDisplayName(d->m_displayName);
     d->m_command->setCodec(codec ? codec : EditorManager::defaultTextCodec());
     d->m_commandResultProxy = new VcsCommandResultProxy(d->m_command.data(), d);
@@ -261,7 +261,7 @@ void VcsBaseDiffEditorController::processCommandOutput(const QString &output)
     d->processDiff(output);
 }
 
-QString VcsBaseDiffEditorController::workingDirectory() const
+FilePath VcsBaseDiffEditorController::workingDirectory() const
 {
     return d->m_directory;
 }
@@ -281,7 +281,7 @@ void VcsBaseDiffEditorController::setDisplayName(const QString &displayName)
     d->m_displayName = displayName;
 }
 
-void VcsBase::VcsBaseDiffEditorController::setWorkingDirectory(const QString &workingDir)
+void VcsBase::VcsBaseDiffEditorController::setWorkingDirectory(const FilePath &workingDir)
 {
     d->m_directory = workingDir;
     setBaseDirectory(workingDir);
diff --git a/src/plugins/vcsbase/vcsbasediffeditorcontroller.h b/src/plugins/vcsbase/vcsbasediffeditorcontroller.h
index 7ccf05fd41b..8c8f58dcdd9 100644
--- a/src/plugins/vcsbase/vcsbasediffeditorcontroller.h
+++ b/src/plugins/vcsbase/vcsbasediffeditorcontroller.h
@@ -55,13 +55,13 @@ public:
     void setProcessEnvironment(const Utils::Environment &value);
     void setVcsBinary(const Utils::FilePath &path);
     void setVcsTimeoutS(int value);
-    void setWorkingDirectory(const QString &workingDir);
+    void setWorkingDirectory(const Utils::FilePath &workingDir);
 
 protected:
     void runCommand(const QList<QStringList> &args, unsigned flags, QTextCodec *codec = nullptr);
     virtual void processCommandOutput(const QString &output);
 
-    QString workingDirectory() const;
+    Utils::FilePath workingDirectory() const;
     void setStartupFile(const QString &startupFile);
     QString startupFile() const;
     void setDisplayName(const QString &displayName);