Git: Use correct line numbers in limited range blame

Change-Id: I12f6fc77b532e5b01f2da6c1c1ff847445447c70
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/git/gitplugin.cpp

@@ -670,6 +670,7 @@ void GitPlugin::blameFile()
     QTC_ASSERT(state.hasFile(), return);
     const int lineNumber = VcsBaseEditor::lineNumberOfCurrentEditor(state.currentFile());
     QStringList extraOptions;
+    int firstLine = -1;
     if (BaseTextEditor *textEditor = BaseTextEditor::currentTextEditor()) {
         QTextCursor cursor = textEditor->textCursor();
         if (cursor.hasSelection()) {
@@ -677,15 +678,25 @@ void GitPlugin::blameFile()
             int selectionStart = cursor.selectionStart();
             int selectionEnd = cursor.selectionEnd();
             cursor.setPosition(selectionStart);
-            argument += QString::number(cursor.blockNumber() + 1) + ',';
+            const int startBlock = cursor.blockNumber();
+            firstLine = startBlock + 1;
+            if (auto widget = qobject_cast<VcsBaseEditorWidget *>(textEditor->widget())) {
+                const int previousFirstLine = widget->firstLineNumber();
+                if (previousFirstLine > 0)
+                    firstLine = previousFirstLine;
+            }
+            argument += QString::number(firstLine) + ',';
             cursor.setPosition(selectionEnd);
-            cursor.blockNumber();
-            argument += QString::number(cursor.blockNumber() + 1);
+            const int endBlock = cursor.blockNumber();
+            argument += QString::number(endBlock + firstLine - startBlock);
             extraOptions << argument;
         }
     }
-    m_gitClient->annotate(state.currentFileTopLevel(), state.relativeCurrentFile(), QString(),
+    VcsBaseEditorWidget *editor = m_gitClient->annotate(
+                state.currentFileTopLevel(), state.relativeCurrentFile(), QString(),
                 lineNumber, extraOptions);
+    if (firstLine > 0)
+        editor->setFirstLineNumber(firstLine);
 }
 
 void GitPlugin::logProject()

src/plugins/vcsbase/vcsbaseeditor.cpp

@@ -561,6 +561,7 @@ public:
     QRegExp m_logEntryPattern;
     QList<int> m_entrySections; // line number where this section starts
     int m_cursorLine = -1;
+    int m_firstLineNumber = -1;
     QString m_annotateRevisionTextFormat;
     QString m_annotatePreviousRevisionTextFormat;
     QString m_copyRevisionTextFormat;
@@ -681,6 +682,37 @@ QString VcsBaseEditorWidget::fileNameForLine(int line) const
     return source();
 }
 
+int VcsBaseEditorWidget::firstLineNumber() const
+{
+    return d->m_firstLineNumber;
+}
+
+void VcsBaseEditorWidget::setFirstLineNumber(int firstLineNumber)
+{
+    d->m_firstLineNumber = firstLineNumber;
+}
+
+QString VcsBaseEditorWidget::lineNumber(int blockNumber) const
+{
+    if (d->m_firstLineNumber > 0)
+        return QString::number(d->m_firstLineNumber + blockNumber);
+    return TextEditorWidget::lineNumber(blockNumber);
+}
+
+int VcsBaseEditorWidget::lineNumberDigits() const
+{
+    if (d->m_firstLineNumber <= 0)
+        return TextEditorWidget::lineNumberDigits();
+
+    int digits = 2;
+    int max = qMax(1, d->m_firstLineNumber + blockCount());
+    while (max >= 100) {
+        max /= 10;
+        ++digits;
+    }
+    return digits;
+}
+
 void VcsBaseEditorWidget::setDescribeSlot(QObject *describeReceiver, const char *describeSlot)
 {
     d->m_describeReceiver = describeReceiver;

src/plugins/vcsbase/vcsbaseeditor.h

@@ -154,6 +154,9 @@ protected:
     virtual bool supportChangeLinks() const;
     virtual QString fileNameForLine(int line) const;
 
+    QString lineNumber(int blockNumber) const override;
+    int lineNumberDigits() const override;
+
 public:
     void finalizeInitialization() override;
     // FIXME: Consolidate these into finalizeInitialization
@@ -199,6 +202,9 @@ public:
     QString workingDirectory() const;
     void setWorkingDirectory(const QString &wd);
 
+    int firstLineNumber() const;
+    void setFirstLineNumber(int firstLineNumber);
+
     bool isModified() const;
 
     EditorContentType contentType() const;