[search] Treat “Đ,đ” as “d” letter in normalization.

2 files changed, 13 insertions, 3 deletions

diff --git a/indexer/indexer_tests/search_string_utils_test.cpp b/indexer/indexer_tests/search_string_utils_test.cpp
index 8278d87ab8..26ed3b52e7 100644
--- a/indexer/indexer_tests/search_string_utils_test.cpp
+++ b/indexer/indexer_tests/search_string_utils_test.cpp
@@ -18,14 +18,20 @@ UNIT_TEST(NormalizeAndSimplifyStringWithOurTambourines)
                         "Iiİı", "iiii",              // Famous turkish "I" letter bug.
                         "ЙЁйёШКИЙй", "йейешкийй",    // Better handling of Russian й letter.
                         "ØøÆ挜", "ooaeaeoeoe",
-                        "バス", "ハス"
+                        "バス", "ハス",
+                        "âàáạăốợồôểềệếỉđưựứửýĂÂĐÊÔƠƯ",
+                        "aaaaaooooeeeeiduuuuyaadeoou",  // Vietnamese
+                        "ăâț", "aat"                    // Romanian
                        };
   */
   string const arr[] = {"ÜbërÅłłęšß", "uberallesss", // Basic test case.
                         "Iiİı", "iiii",              // Famous turkish "I" letter bug.
                         "ЙЁйёШКИЙй", "иеиешкиии",    // Better handling of Russian й letter.
-                        "ØøÆ挜", "ooaeaeoeoe",
-                        "バス", "ハス"
+                        "ØøÆ挜", "ooaeaeoeoe",      // Dansk
+                        "バス", "ハス",
+                        "âàáạăốợồôểềệếỉđưựứửýĂÂĐÊÔƠƯ",
+                        "aaaaaooooeeeeiduuuuyaadeoou",  // Vietnamese
+                        "ăâț", "aat"                    // Romanian
                        };
 
   for (size_t i = 0; i < ARRAY_SIZE(arr); i += 2)
diff --git a/indexer/search_string_utils.hpp b/indexer/search_string_utils.hpp
index d27e43991a..86c9b10092 100644
--- a/indexer/search_string_utils.hpp
+++ b/indexer/search_string_utils.hpp
@@ -17,6 +17,10 @@ inline strings::UniString NormalizeAndSimplifyString(string const & s)
     UniChar & c = uniString[i];
     switch (c)
     {
+    // Replace "d with stroke" to simple d letter. Used in Vietnamese.
+    // (unicode-compliant implementation leaves it unchanged)
+    case 0x0110:
+    case 0x0111: c = 'd'; break;
     // Replace small turkish dotless 'ı' with dotted 'i'.
     // Our own invented hack to avoid well-known Turkish I-letter bug.
     case 0x0131: c = 'i'; break;