diff --git a/src/libs/utils/differ.cpp b/src/libs/utils/differ.cpp
index b1c163bb5b4..9dc2ce8454e 100644
--- a/src/libs/utils/differ.cpp
+++ b/src/libs/utils/differ.cpp
@@ -936,7 +936,7 @@ QString Diff::toString() const
 
 ///////////////
 
-Differ::Differ(const QFuture<void> &future)
+Differ::Differ(const std::optional<QFuture<void>> &future)
     : m_future(future)
 {
 }
@@ -1073,7 +1073,7 @@ QList<Diff> Differ::diffMyers(const QString &text1, const QString &text2)
     int kMinReverse = -D;
     int kMaxReverse = D;
     for (int d = 0; d <= D; d++) {
-        if (m_future.isCanceled()) {
+        if (m_future && m_future->isCanceled()) {
             delete [] forwardV;
             delete [] reverseV;
             return QList<Diff>();
@@ -1192,7 +1192,7 @@ QList<Diff> Differ::diffNonCharMode(const QString &text1, const QString &text2)
     QString lastInsert;
     QList<Diff> newDiffList;
     for (int i = 0; i <= diffList.count(); i++) {
-        if (m_future.isCanceled()) {
+        if (m_future && m_future->isCanceled()) {
             m_currentDiffMode = diffMode;
             return {};
         }
diff --git a/src/libs/utils/differ.h b/src/libs/utils/differ.h
index 09b79652225..dc6d74f30da 100644
--- a/src/libs/utils/differ.h
+++ b/src/libs/utils/differ.h
@@ -8,6 +8,8 @@
 #include <QFuture>
 #include <QString>
 
+#include <optional>
+
 QT_BEGIN_NAMESPACE
 template <class K, class T>
 class QMap;
@@ -42,7 +44,7 @@ public:
         WordMode,
         LineMode
     };
-    Differ(const QFuture<void> &future = {});
+    Differ(const std::optional<QFuture<void>> &future = {});
     QList<Diff> diff(const QString &text1, const QString &text2);
     QList<Diff> unifiedDiff(const QString &text1, const QString &text2);
     void setDiffMode(DiffMode mode);
@@ -90,7 +92,7 @@ private:
                        int subTextStart);
     DiffMode m_diffMode = Differ::LineMode;
     DiffMode m_currentDiffMode = Differ::LineMode;
-    QFuture<void> m_future;
+    std::optional<QFuture<void>> m_future;
 };
 
 } // namespace Utils
diff --git a/src/plugins/diffeditor/diffutils.cpp b/src/plugins/diffeditor/diffutils.cpp
index efea3530a43..afb75203037 100644
--- a/src/plugins/diffeditor/diffutils.cpp
+++ b/src/plugins/diffeditor/diffutils.cpp
@@ -557,7 +557,7 @@ static QList<RowData> readLines(QStringView patch, bool lastChunk, bool *lastChu
     int noNewLineInDelete = -1;
     int noNewLineInInsert = -1;
 
-    const QVector<QStringView> lines = patch.split(newLine);
+    const QList<QStringView> lines = patch.split(newLine);
     int i;
     for (i = 0; i < lines.size(); i++) {
         QStringView line = lines.at(i);
@@ -795,7 +795,7 @@ static QList<ChunkData> readChunks(QStringView patch, bool *lastChunkAtTheEndOfF
     QList<ChunkData> chunkDataList;
     int position = -1;
 
-    QVector<int> startingPositions; // store starting positions of @@
+    QList<int> startingPositions; // store starting positions of @@
     if (patch.startsWith(QStringLiteral("@@ -")))
         startingPositions.append(position + 1);
 
@@ -1199,7 +1199,7 @@ static void readGitPatch(QPromise<QList<FileData>> &promise, QStringView patch)
 {
     int position = -1;
 
-    QVector<int> startingPositions; // store starting positions of git headers
+    QList<int> startingPositions; // store starting positions of git headers
     if (patch.startsWith(QStringLiteral("diff --git ")))
         startingPositions.append(position + 1);
 
@@ -1214,7 +1214,7 @@ static void readGitPatch(QPromise<QList<FileData>> &promise, QStringView patch)
 
     const QChar newLine('\n');
 
-    QVector<PatchInfo> patches;
+    QList<PatchInfo> patches;
     const int count = startingPositions.size();
     for (int i = 0; i < count; i++) {
         if (promise.isCanceled())
@@ -1239,10 +1239,12 @@ static void readGitPatch(QPromise<QList<FileData>> &promise, QStringView patch)
         patches.append(PatchInfo { remainingFileDiff, fileData });
     }
 
+    if (patches.isEmpty())
+        return;
+
     promise.setProgressRange(0, patches.size());
 
     QList<FileData> fileDataList;
-    bool readOk = false;
     int i = 0;
     for (const auto &patchInfo : std::as_const(patches)) {
         if (promise.isCanceled())
@@ -1250,6 +1252,7 @@ static void readGitPatch(QPromise<QList<FileData>> &promise, QStringView patch)
         promise.setProgressValue(i++);
 
         FileData fileData = patchInfo.fileData;
+        bool readOk = false;
         if (!patchInfo.patch.isEmpty() || fileData.fileOperation == FileData::ChangeFile)
             fileData.chunks = readChunks(patchInfo.patch, &fileData.lastChunkAtTheEndOfFile, &readOk);
         else