DiffEditor: fix revert chunk for diffs of modified files

Apply chunk action doesn't make sense for that case,
will stay disabled.

Task-number: QTCREATORBUG-17136
Change-Id: Idce31b3aa9d354536a01607c10b20273158961d5
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/diffeditor/diffeditordocument.cpp

@@ -87,7 +87,9 @@ DiffEditorController *DiffEditorDocument::controller() const
     return m_controller;
 }
 
-QString DiffEditorDocument::makePatch(int fileIndex, int chunkIndex, bool revert, bool addPrefix) const
+QString DiffEditorDocument::makePatch(int fileIndex, int chunkIndex,
+                                      bool revert, bool addPrefix,
+                                      const QString &overriddenFileName) const
 {
     if (fileIndex < 0 || chunkIndex < 0)
         return QString();
@@ -102,9 +104,10 @@ QString DiffEditorDocument::makePatch(int fileIndex, int chunkIndex, bool revert
     const ChunkData &chunkData = fileData.chunks.at(chunkIndex);
     const bool lastChunk = (chunkIndex == fileData.chunks.count() - 1);
 
-    const QString fileName = revert
-            ? fileData.rightFileInfo.fileName
-            : fileData.leftFileInfo.fileName;
+    const QString fileName = !overriddenFileName.isEmpty()
+            ? overriddenFileName : revert
+              ? fileData.rightFileInfo.fileName
+              : fileData.leftFileInfo.fileName;
 
     QString leftPrefix, rightPrefix;
     if (addPrefix) {

src/plugins/diffeditor/diffeditordocument.h

@@ -46,7 +46,9 @@ public:
 
     DiffEditorController *controller() const;
 
-    QString makePatch(int fileIndex, int chunkIndex, bool revert, bool addPrefix = false) const;
+    QString makePatch(int fileIndex, int chunkIndex,
+                      bool revert, bool addPrefix = false,
+                      const QString &overriddenFileName = QString()) const;
 
     void setDiffFiles(const QList<FileData> &data, const QString &directory,
                       const QString &startupFile = QString());

src/plugins/diffeditor/diffeditorplugin.cpp

@@ -143,6 +143,7 @@ void DiffCurrentFileController::reload()
         fileData.rightFileInfo.fileName = m_fileName;
         fileData.leftFileInfo.typeInfo = tr("Saved");
         fileData.rightFileInfo.typeInfo = tr("Modified");
+        fileData.rightFileInfo.patchBehaviour = DiffFileInfo::PatchEditor;
 
         if (!leftFileExists)
             fileData.fileOperation = FileData::NewFile;
@@ -201,6 +202,7 @@ void DiffOpenFilesController::reload()
             fileData.rightFileInfo.fileName = fileName;
             fileData.leftFileInfo.typeInfo = tr("Saved");
             fileData.rightFileInfo.typeInfo = tr("Modified");
+            fileData.rightFileInfo.patchBehaviour = DiffFileInfo::PatchEditor;
 
             if (!leftFileExists)
                 fileData.fileOperation = FileData::NewFile;
@@ -261,6 +263,7 @@ void DiffModifiedFilesController::reload()
             fileData.rightFileInfo.fileName = fileName;
             fileData.leftFileInfo.typeInfo = tr("Saved");
             fileData.rightFileInfo.typeInfo = tr("Modified");
+            fileData.rightFileInfo.patchBehaviour = DiffFileInfo::PatchEditor;
 
             if (!leftFileExists)
                 fileData.fileOperation = FileData::NewFile;

src/plugins/diffeditor/diffeditorwidgetcontroller.cpp

@@ -32,6 +32,7 @@
 #include <coreplugin/patchtool.h>
 
 #include <texteditor/fontsettings.h>
+#include <texteditor/textdocument.h>
 
 #include <extensionsystem/pluginmanager.h>
 
@@ -42,6 +43,7 @@
 #include <QDir>
 #include <QMenu>
 #include <QMessageBox>
+#include <QTemporaryFile>
 #include <QTextCodec>
 
 using namespace Core;
@@ -77,27 +79,60 @@ void DiffEditorWidgetController::patch(bool revert)
         return;
     }
 
-    const int strip = m_document->baseDirectory().isEmpty() ? -1 : 0;
-
     const FileData fileData = m_contextFileData.at(m_contextMenuFileIndex);
     const QString fileName = revert
             ? fileData.rightFileInfo.fileName
             : fileData.leftFileInfo.fileName;
+    const DiffFileInfo::PatchBehaviour patchBehaviour = revert
+            ? fileData.rightFileInfo.patchBehaviour
+            : fileData.leftFileInfo.patchBehaviour;
 
     const QString workingDirectory = m_document->baseDirectory().isEmpty()
             ? QFileInfo(fileName).absolutePath()
             : m_document->baseDirectory();
+    const QString absFileName = QFileInfo(workingDirectory + '/' + QFileInfo(fileName).fileName()).absoluteFilePath();
 
-    const QString patch = m_document->makePatch(m_contextMenuFileIndex, m_contextMenuChunkIndex, revert);
+    if (patchBehaviour == DiffFileInfo::PatchFile) {
+        const int strip = m_document->baseDirectory().isEmpty() ? -1 : 0;
 
-    if (patch.isEmpty())
-        return;
+        const QString patch = m_document->makePatch(m_contextMenuFileIndex, m_contextMenuChunkIndex, revert);
 
-    const QString absFileName = QFileInfo(workingDirectory + '/' + fileName).absoluteFilePath();
-    FileChangeBlocker fileChangeBlocker(absFileName);
-    if (PatchTool::runPatch(EditorManager::defaultTextCodec()->fromUnicode(patch),
-                            workingDirectory, strip, revert))
-        m_document->reload();
+        if (patch.isEmpty())
+            return;
+
+        FileChangeBlocker fileChangeBlocker(absFileName);
+        if (PatchTool::runPatch(EditorManager::defaultTextCodec()->fromUnicode(patch),
+                                workingDirectory, strip, revert))
+            m_document->reload();
+    } else { // PatchEditor
+        TextEditor::TextDocument *textDocument = qobject_cast<TextEditor::TextDocument *>(
+                    DocumentModel::documentForFilePath(absFileName));
+        if (!textDocument)
+            return;
+
+        QTemporaryFile contentsCopy;
+        if (!contentsCopy.open())
+            return;
+
+        contentsCopy.write(textDocument->contents());
+        contentsCopy.close();
+
+        const QString contentsCopyFileName = contentsCopy.fileName();
+        const QString contentsCopyDir = QFileInfo(contentsCopyFileName).absolutePath();
+
+        const QString patch = m_document->makePatch(m_contextMenuFileIndex,
+                              m_contextMenuChunkIndex, revert, false, QFileInfo(contentsCopyFileName).fileName());
+
+        if (patch.isEmpty())
+            return;
+
+        if (PatchTool::runPatch(EditorManager::defaultTextCodec()->fromUnicode(patch),
+                                contentsCopyDir, 0, revert)) {
+            QString errorString;
+            if (textDocument->reload(&errorString, contentsCopyFileName))
+                m_document->reload();
+        }
+    }
 }
 
 void DiffEditorWidgetController::jumpToOriginalFile(const QString &fileName,

src/plugins/diffeditor/diffutils.h

@@ -38,12 +38,18 @@ class Diff;
 
 class DIFFEDITOR_EXPORT DiffFileInfo {
 public:
+    enum PatchBehaviour {
+        PatchFile,
+        PatchEditor
+    };
+
     DiffFileInfo() {}
     DiffFileInfo(const QString &file) : fileName(file) {}
     DiffFileInfo(const QString &file, const QString &type)
         : fileName(file), typeInfo(type) {}
     QString fileName;
     QString typeInfo;
+    PatchBehaviour patchBehaviour = PatchFile;
 };
 
 class DIFFEDITOR_EXPORT TextLineData {