diff -r ee70b17950bd -r 80e129ec3408 src/lib/BasicUnescapingINIHandler.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/lib/BasicUnescapingINIHandler.h	Wed Nov 25 21:50:26 2020 +0100
@@ -0,0 +1,74 @@
+/**
+ * Relational pipes
+ * Copyright © 2020 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+
+#include <sstream>
+
+#include "UnescapingINIHandler.h"
+
+using namespace std;
+using namespace relpipe::writer;
+
+namespace relpipe {
+namespace in {
+namespace ini {
+namespace lib {
+
+class BasicUnescapingINIContentHandler : public UnescapingINIContentHandler {
+protected:
+
+	virtual std::string unescape(const std::string& s) {
+		std::stringstream result;
+		for (int i = 0, length = s.size(); i < length; i++) {
+			char ch = s[i];
+			if (i + 1 < length && ch == ESC) {
+				ch = s[i + 1];
+				if (ch == 'n') put(result, '\n', i);
+				else if (ch == 'r') put(result, '\r', i);
+				else if (ch == 't') put(result, '\t', i);
+				else if (ch == 's') put(result, ' ', i); // TODO: Reconsider what is „basic“ escaping and should be supported.
+				else if (ch == '"') put(result, ch, i); //        The delimiters (\n,]",') are already unescaped during the first stage in the INIReader while parsing (the delimiter relevant to given environment is unescaped, e.g. \" in "quoted" value).
+				else if (ch == '\'') put(result, ch, i); //       So it does not necessary to do it here. But someone might write a="xxx\'zzz" however it is superfluous because a="xxx'zzz" will also work.
+				else if (ch == ']') put(result, ch, i);
+				else if (ch == ':') put(result, ch, i);
+				else if (ch == ';') put(result, ch, i);
+				else if (ch == '#') put(result, ch, i);
+				else if (ch == '=') put(result, ch, i);
+				else if (ch == ESC && !lastEscaphingPhase) put(result, ESC, i).put(ESC); // copy and skip even the second \ to avoid its misinterpretation in the next cycle
+				else if (ch == ESC && lastEscaphingPhase) put(result, ESC, i); // unescape \\ to \.
+				else if (lastEscaphingPhase) throw std::logic_error(std::string("Unsupported escape sequence: ") + ch);
+				else result.put(ESC); // keep the escape sequence for later unescaping phase
+			} else if (ch == ESC) {
+				throw std::logic_error(std::string("Missing escape sequence")); // this should not happen
+			} else {
+				result.put(ch);
+			}
+		}
+		return result.str();
+	}
+
+public:
+
+	BasicUnescapingINIContentHandler(INIContentHandler& output, bool lastEscaphingPhase) : UnescapingINIContentHandler(output, lastEscaphingPhase) {
+	}
+
+};
+
+}
+}
+}
+}