DiffEditor: Fix no newline handling

Change-Id: I3278ae80d7ee010942122723b3e8bb8c729e7182
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/diffeditor/diffeditorplugin.cpp

@@ -297,6 +297,25 @@ void DiffEditor::Internal::DiffEditorPlugin::testMakePatch_data()
 
     ///////////
 
+    rows.clear();
+    rows << RowData(_("ABCD"));
+    rows << RowData(_(""), TextLineData::Separator);
+    rows << RowData(_(""), TextLineData::Separator);
+    chunk.rows = rows;
+    patchText = header + _("@@ -1,2 +1,1 @@\n"
+                           "-ABCD\n"
+                           "-\n"
+                           "+ABCD\n"
+                           "\\ No newline at end of file\n");
+
+    QTest::newRow("Two last EOLs removed") << chunk
+                            << fileName
+                            << fileName
+                            << true
+                            << patchText;
+
+    ///////////
+
     rows.clear();
     rows << RowData(_("ABCD"));
     rows << RowData(TextLineData::Separator, _(""));
@@ -418,6 +437,26 @@ void DiffEditor::Internal::DiffEditorPlugin::testMakePatch_data()
             << fileName
             << false
             << patchText;
+
+    ///////////
+
+    rows.clear();
+    rows << RowData(_("ABCD"));
+    rows << RowData(TextLineData::Separator, _(""));
+    rows << RowData(_(""), _("EFGH"));
+    chunk.rows = rows;
+    patchText = header + _("@@ -1,1 +1,3 @@\n"
+                           " ABCD\n"
+                           "+\n"
+                           "+EFGH\n"
+                           "\\ No newline at end of file\n");
+
+    QTest::newRow("Blank line followed by No newline")
+            << chunk
+            << fileName
+            << fileName
+            << true
+            << patchText;
 }
 
 void DiffEditor::Internal::DiffEditorPlugin::testMakePatch()
@@ -748,6 +787,37 @@ void DiffEditor::Internal::DiffEditorPlugin::testReadPatch_data()
 
     QTest::newRow("2 chunks - first ends with blank line") << patch
                                 << fileDataList4;
+
+    //////////////
+
+    patch = _("diff --git a/file foo.txt b/file foo.txt\n"
+              "index 1234567..9876543 100644\n"
+              "--- a/file foo.txt\n"
+              "+++ b/file foo.txt\n"
+              "@@ -1,1 +1,3 @@ void DiffEditor::ctor()\n"
+              " ABCD\n"
+              "+\n"
+              "+EFGH\n"
+              "\\ No newline at end of file\n");
+
+    fileData1.leftFileInfo = DiffFileInfo(_("file foo.txt"), _("1234567"));
+    fileData1.rightFileInfo = DiffFileInfo(_("file foo.txt"), _("9876543"));
+    fileData1.fileOperation = FileData::ChangeFile;
+    chunkData1.leftStartingLineNumber = 0;
+    chunkData1.rightStartingLineNumber = 0;
+    rows1.clear();
+    rows1 << RowData(_("ABCD"));
+    rows1 << RowData(TextLineData::Separator, _(""));
+    rows1 << RowData(_(""), _("EFGH"));
+    chunkData1.rows = rows1;
+    fileData1.chunks.clear();
+    fileData1.chunks << chunkData1;
+
+    QList<FileData> fileDataList5;
+    fileDataList5 << fileData1;
+
+    QTest::newRow("Blank line followed by No newline") << patch
+                                << fileDataList5;
 }
 
 void DiffEditor::Internal::DiffEditorPlugin::testReadPatch()

src/plugins/diffeditor/diffutils.cpp

@@ -362,15 +362,33 @@ QString DiffUtils::makePatch(const ChunkData &chunkData,
     int rightLineCount = 0;
     QList<TextLineData> leftBuffer, rightBuffer;
 
-    int lastEqualRow = -1;
+    int rowToBeSplit = -1;
+
     if (lastChunk) {
-        for (int i = chunkData.rows.count(); i > 0; i--) {
-            if (chunkData.rows.at(i - 1).equal) {
-                if (i != chunkData.rows.count())
-                    lastEqualRow = i - 1;
+        // Detect the case when the last equal line is followed by
+        // only separators on left or on right. In that case
+        // the last equal line needs to be split.
+        const int rowCount = chunkData.rows.count();
+        int i = 0;
+        for (i = rowCount; i > 0; i--) {
+            const RowData &rowData = chunkData.rows.at(i - 1);
+            if (rowData.leftLine.textLineType != TextLineData::Separator
+                    || rowData.rightLine.textLineType != TextLineData::TextLine)
                 break;
-            }
         }
+        const int leftSeparator = i;
+        for (i = rowCount; i > 0; i--) {
+            const RowData &rowData = chunkData.rows.at(i - 1);
+            if (rowData.rightLine.textLineType != TextLineData::Separator
+                    || rowData.leftLine.textLineType != TextLineData::TextLine)
+                break;
+        }
+        const int rightSeparator = i;
+        const int commonSeparator = qMin(leftSeparator, rightSeparator);
+        if (commonSeparator > 0
+                && commonSeparator < rowCount
+                && chunkData.rows.at(commonSeparator - 1).equal)
+            rowToBeSplit = commonSeparator - 1;
     }
 
     for (int i = 0; i <= chunkData.rows.count(); i++) {
@@ -379,7 +397,7 @@ QString DiffUtils::makePatch(const ChunkData &chunkData,
                 : RowData(TextLineData(TextLineData::Separator)); // dummy,
                                         // ensure we process buffers to the end.
                                         // rowData will be equal
-        if (rowData.equal && i != lastEqualRow) {
+        if (rowData.equal && i != rowToBeSplit) {
             if (leftBuffer.count()) {
                 for (int j = 0; j < leftBuffer.count(); j++) {
                     const QString line = makePatchLine(QLatin1Char('-'),
@@ -530,8 +548,6 @@ static QList<RowData> readLines(const QString &patch,
                 Diff &last = diffList.last();
                 if (last.text.isEmpty())
                     break;
-                if (last.text.at(0) == newLine) // there is a new line
-                    break;
 
                 if (last.command == Diff::Equal) {
                     if (noNewLineInEqual >= 0)