DiffEditor: Save description along with diff.

Save complete, git-applicable patch when saving the result of
for example 'git show'. Strips some Creator-specific tags
off the description and reformats the description such
that it is accepted by git.

Change-Id: I739d85a7263f97e2149a2794974ba026f2eca067
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/diffeditor/diffeditorcontroller.cpp

@@ -102,6 +102,44 @@ bool DiffEditorController::isIgnoreWhitespace() const
     return m_ignoreWhitespace;
 }
 
+// ### fixme: git-specific handling should be done in the git plugin:
+// Remove unexpanded branches and follows-tag, clear indentation
+// and create E-mail
+static void formatGitDescription(QString *description)
+{
+    QString result;
+    result.reserve(description->size());
+    foreach (QString line, description->split(QLatin1Char('\n'))) {
+        if (line.startsWith(QLatin1String("commit "))
+            || line.startsWith(QLatin1String("Branches: <Expand>"))) {
+            continue;
+        }
+        if (line.startsWith(QLatin1String("Author: ")))
+            line.replace(0, 8, QStringLiteral("From: "));
+        else if (line.startsWith(QLatin1String("    ")))
+            line.remove(0, 4);
+        result.append(line);
+        result.append(QLatin1Char('\n'));
+    }
+    *description = result;
+}
+
+QString DiffEditorController::contents() const
+{
+    QString result = m_description;
+    const int formattingOptions = DiffUtils::GitFormat;
+    if (formattingOptions & DiffUtils::GitFormat)
+        formatGitDescription(&result);
+
+    const QString diff = DiffUtils::makePatch(diffFiles(), formattingOptions);
+    if (!diff.isEmpty()) {
+        if (!result.isEmpty())
+            result += QLatin1Char('\n');
+        result += diff;
+    }
+    return result;
+}
+
 QString DiffEditorController::makePatch(bool revert, bool addPrefix) const
 {
     if (m_diffFileIndex < 0 || m_chunkIndex < 0)

src/plugins/diffeditor/diffeditorcontroller.h

@@ -57,6 +57,7 @@ public:
     bool isIgnoreWhitespace() const;
 
     QString makePatch(bool revert, bool addPrefix = false) const;
+    QString contents() const;
 
     DiffEditorReloader *reloader() const;
     void setReloader(DiffEditorReloader *reloader);

src/plugins/diffeditor/diffeditordocument.cpp

@@ -78,9 +78,7 @@ bool DiffEditorDocument::save(QString *errorString, const QString &fileName, boo
     Q_UNUSED(errorString)
     Q_UNUSED(autoSave)
 
-    const QString contents = DiffUtils::makePatch(m_controller->diffFiles());
-
-    const bool ok = write(fileName, format(), contents, errorString);
+    const bool ok = write(fileName, format(), m_controller->contents(), errorString);
 
     if (!ok)
         return false;

src/plugins/diffeditor/diffutils.cpp

@@ -31,6 +31,7 @@
 #include "diffutils.h"
 #include "differ.h"
 #include <QStringList>
+#include <QTextStream>
 #include "texteditor/fontsettings.h"
 
 namespace DiffEditor {
@@ -483,31 +484,35 @@ QString DiffUtils::makePatch(const ChunkData &chunkData,
     return diffText;
 }
 
-QString DiffUtils::makePatch(const QList<FileData> &fileDataList)
+QString DiffUtils::makePatch(const QList<FileData> &fileDataList, unsigned formatFlags)
 {
     QString diffText;
+    QTextStream str(&diffText);
 
     for (int i = 0; i < fileDataList.count(); i++) {
         const FileData &fileData = fileDataList.at(i);
-
+        if (formatFlags & GitFormat) {
+            str << "diff --git a/" << fileData.leftFileInfo.fileName
+                << " b/" << fileData.rightFileInfo.fileName << '\n';
+        }
         if (fileData.binaryFiles) {
-            const QString binaryLine = QLatin1String("Binary files ")
-                    + fileData.leftFileInfo.fileName
-                    + QLatin1String(" and ")
-                    + fileData.rightFileInfo.fileName
-                    + QLatin1String(" differ\n");
-            diffText += binaryLine;
+            str << "Binary files ";
+            if (formatFlags & AddLevel)
+                str << "a/";
+            str << fileData.leftFileInfo.fileName << " and ";
+            if (formatFlags & AddLevel)
+                str << "b/";
+            str << fileData.rightFileInfo.fileName << " differ\n";
         } else {
-            const QString leftFileInfo = QLatin1String("--- ")
-                    + fileData.leftFileInfo.fileName + QLatin1Char('\n');
-            const QString rightFileInfo = QLatin1String("+++ ")
-                    + fileData.rightFileInfo.fileName + QLatin1Char('\n');
-
-            diffText += leftFileInfo;
-            diffText += rightFileInfo;
-
+            str << "--- ";
+            if (formatFlags & AddLevel)
+                str << "a/";
+            str << fileData.leftFileInfo.fileName << "\n+++ ";
+            if (formatFlags & AddLevel)
+                str << "b/";
+            str << fileData.rightFileInfo.fileName << '\n';
             for (int j = 0; j < fileData.chunks.count(); j++) {
-                diffText += makePatch(fileData.chunks.at(j),
+                str << makePatch(fileData.chunks.at(j),
                                       (j == fileData.chunks.count() - 1)
                                       && fileData.lastChunkAtTheEndOfFile);
             }

src/plugins/diffeditor/diffutils.h

@@ -130,6 +130,10 @@ public:
 
 class DIFFEDITOR_EXPORT DiffUtils {
 public:
+    enum PatchFormattingFlags {
+        AddLevel = 0x1, // Add 'a/' , '/b' for git am
+        GitFormat = AddLevel | 0x2, // Add line 'diff ..' as git does
+    };
 
     static ChunkData calculateOriginalData(const QList<Diff> &leftDiffList,
                                            const QList<Diff> &rightDiffList);
@@ -146,7 +150,8 @@ public:
                              const QString &leftFileName,
                              const QString &rightFileName,
                              bool lastChunk = false);
-    static QString makePatch(const QList<FileData> &fileDataList);
+    static QString makePatch(const QList<FileData> &fileDataList,
+                             unsigned formatFlags = 0);
     static QList<FileData> readPatch(const QString &patch,
                                      bool *ok = 0);
 };