Git: Fix Precedes/Follows display for show opened from log

Change-Id: Ib999f8f00b065e4e51b70f1c5f81bdd17baabd8c
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/git/giteditor.cpp

@@ -192,7 +192,7 @@ void GitEditor::setPlainTextDataFiltered(const QByteArray &a)
     }
     case VcsBase::DiffOutput: {
         const QFileInfo fi(source());
-        const QString workingDirectory = fi.absolutePath();
+        const QString workingDirectory = fi.isDir() ? fi.absoluteFilePath() : fi.absolutePath();
         QByteArray precedes, follows;
         if (array.startsWith("commit ")) { // show
             int lastHeaderLine = array.indexOf("\n\n") + 1;