Fehler behoben: Umlaute, Latin-1, Fehlermeldungen, atomares Schreiben

Spaltennamen mit Umlauten in Ausdrücken, Latin-1-Dateien als UTF-8,
Fehler als eine Zeile (RDB_DEBUG=1 für Backtrace), Werte mit Tab oder
Zeilenumbruch abgelehnt, Tabellen und Indexe über Temp-Datei und rename,
update.rdb gibt den Satz bei Editorfehler zurück, sorttable -r stabil.

test/rdb_test.rb

@@ -876,3 +876,51 @@ class TaxTablesTest < RdbCase
     end
   end
 end
+
+class RobustnessTest < RdbCase
+  def test_umlauts_in_column_names
+    write('uml', "Größe\tÜber\n-----\t----\n5\t7\n1\t2\n")
+    assert_equal ['5', '7'], data(rdb('row', 'Über > 3', file: 'uml')).first
+    assert_equal 1, data(rdb('row', 'Größe > 3', file: 'uml')).size
+  end
+
+  def test_latin1_data_is_read_and_written_as_utf8
+    File.binwrite(File.join(@dir, 'lat'), "Name\n----\n\xE4pfel\n")
+    assert_equal "Äpfel".downcase, data(rdb('row', 'Name ~ /pfel/', file: 'lat')).first.first
+  end
+
+  def test_errors_are_one_line_not_a_backtrace
+    _o, e, st = run3('update.rdb', 'inventory', stdin: "/[\n")
+    refute st.success?
+    assert_match(/update\.rdb: .*char-class/, e)
+    refute_match(/\.rb:\d+:in/, e)
+  end
+
+  def test_enter_refuses_a_value_with_a_tab
+    _o, e, st = run3('enter', '-1', 'inventory', stdin: "9\t9\n1\n2\n3\nthing\n")
+    refute st.success?
+    assert_match(/contains a tab/, e)
+  end
+
+  def test_sorttable_reverse_keeps_ties_in_order
+    out = rdb('sorttable', '-r', 'B', stdin: "A\tB\n-\t-\n1\tb\n2\ta\n3\tb\n4\ta\n")
+    assert_equal %w[1 3 2 4], data(out).map(&:first)
+  end
+
+  def test_update_keeps_the_record_when_the_editor_fails
+    before = File.read(File.join(@dir, 'inventory'))
+    _o, e, = run3('update.rdb', 'inventory', stdin: "1\ne\nq\n", env: { 'EDITOR' => 'false' })
+    assert_match(/editor false failed/, e)
+    assert_equal before, File.read(File.join(@dir, 'inventory'))
+  end
+
+  def test_write_file_is_complete_and_keeps_the_mode
+    path = File.join(@dir, 'wf')
+    File.write(path, 'old')
+    File.chmod(0o640, path)
+    Rdb.write_file(path, 'new')
+    assert_equal 'new', File.read(path)
+    assert_equal 0o640, File.stat(path).mode & 0o777
+    assert_empty Dir[File.join(@dir, 'wf.tmp*')]
+  end
+end