added two tests for partial word and case tolerance in mnemonics

tests/unit_tests/mnemonics.cpp

@@ -51,6 +51,7 @@
 #include "mnemonics/english_old.h"
 #include "mnemonics/language_base.h"
 #include "mnemonics/singleton.h"
+#include <boost/algorithm/string.hpp>
 
 namespace
 {
@@ -221,3 +222,38 @@ TEST(mnemonics, utf8prefix)
   ASSERT_TRUE(Language::utf8prefix(epee::wipeable_string("æon"), 3) == "æon");
   ASSERT_TRUE(Language::utf8prefix(epee::wipeable_string("æon"), 4) == "æon");
 }
+
+TEST(mnemonics, case_tolerance)
+{
+    bool res;
+    //
+    crypto::secret_key key_1;
+    std::string language_name_1;
+    const std::string seed_1 = "Neubau umarmen Abart umarmen Turban feilen Brett Bargeld Episode Milchkuh Substanz Jahr Armband Maibaum Tand Grünalge Tabak erziehen Federboa Lobrede Tenor Leuchter Curry Diskurs Tenor";
+    res = crypto::ElectrumWords::words_to_bytes(seed_1, key_1, language_name_1);
+    ASSERT_EQ(true, res);
+    ASSERT_STREQ(language_name_1.c_str(), "Deutsch");
+    //
+    crypto::secret_key key_2;
+    std::string language_name_2;
+    // neubau is capitalized in the word list, but the language detection code should be able to detect it as Deutsch
+    std::string seed_2 = "neubau umarmen Abart umarmen Turban feilen Brett Bargeld Episode Milchkuh Substanz Jahr Armband Maibaum Tand Grünalge Tabak erziehen Federboa Lobrede Tenor Leuchter Curry Diskurs tenor";
+    boost::algorithm::to_lower(seed_2);
+    res = crypto::ElectrumWords::words_to_bytes(seed_2, key_2, language_name_2);
+    ASSERT_EQ(true, res);
+    ASSERT_STREQ(language_name_2.c_str(), "Deutsch");
+    //
+    ASSERT_TRUE(key_1 == key_2);
+}
+
+TEST(mnemonics, partial_word_tolerance)
+{
+    bool res;
+    //
+    crypto::secret_key key_1;
+    std::string language_name_1;
+    const std::string seed_1 = "crim bam scamp gna limi woma wron tuit birth mundane donuts square cohesive dolphin titans narrate fue saved wrap aloof magic mirr toget upda wra";
+    res = crypto::ElectrumWords::words_to_bytes(seed_1, key_1, language_name_1);
+    ASSERT_EQ(true, res);
+    ASSERT_STREQ(language_name_1.c_str(), "English");
+}