correct _nu_tolower/_nu_toupper usage

1 files changed, 50 insertions, 30 deletions

diff --git a/platform/default/string_stdlib.cpp b/platform/default/string_stdlib.cpp
index 3b89a45043..ba55542208 100644
--- a/platform/default/string_stdlib.cpp
+++ b/platform/default/string_stdlib.cpp
@@ -6,51 +6,71 @@
 #include <libnu/libnu.h>
 #include <cstring>
 
-namespace mbgl {
-namespace platform {
+namespace mbgl { namespace platform {
 
-std::string uppercase(const std::string& str)
+std::string uppercase(std::string const& str)
 {
-    boost::u8_to_u32_iterator<std::string::const_iterator> itr(str.begin());
-    boost::u8_to_u32_iterator<std::string::const_iterator> end(str.end());
-    std::string output;
-    char buf[5];
-    for (; itr!=end; ++itr)
+    std::stringstream output;
+    char const *itr = str.c_str(), *nitr = itr;
+    char const *end = itr + str.length();
+    char lo[5] = { 0 };
+
+    for (; itr < end; itr = nitr)
     {
-        char const* up = nu_toupper(*itr);
-        if (up != 0) output.append(up);
+        uint32_t code_point = 0;
+        char const* buf = 0;
+
+        nitr = _nu_toupper(itr, end, nu_utf8_read, &code_point, &buf, 0);
+        if (buf != 0)
+        {
+            do
+            {
+                buf = NU_CASEMAP_DECODING_FUNCTION(buf, &code_point);
+                if (code_point == 0) break;
+                output.write(lo, nu_utf8_write(code_point, lo) - lo);
+            }
+            while (code_point != 0);
+        }
         else
         {
-            std::memset(buf, 0, 5);
-            nu_utf8_write(*itr, buf);
-            output.append(buf);
+            output.write(itr, nitr - itr);
         }
     }
-    return output;
+
+    return output.str();
+
 }
 
-std::string lowercase(const std::string& str)
+std::string lowercase(std::string const& str)
 {
-    std::string output;
-    char lo[5];
-    char const* itr = str.c_str();
-    char const* end = itr + str.length();
-    char const* buf = 0;
-    uint32_t code_point;
-    for ( ; itr!=end;)
+    std::stringstream output;
+    char const *itr = str.c_str(), *nitr = itr;
+    char const *end = itr + str.length();
+    char lo[5] = { 0 };
+
+    for (; itr < end; itr = nitr)
     {
+        uint32_t code_point = 0;
+        char const* buf = 0;
 
-        itr = _nu_tolower(itr, end, nu_utf8_read, &code_point, &buf, 0);
-        if (buf != 0) output.append(buf);
+        nitr = _nu_tolower(itr, end, nu_utf8_read, &code_point, &buf, 0);
+        if (buf != 0)
+        {
+            do
+            {
+                buf = NU_CASEMAP_DECODING_FUNCTION(buf, &code_point);
+                if (code_point == 0) break;
+                output.write(lo, nu_utf8_write(code_point, lo) - lo);
+            }
+            while (code_point != 0);
+        }
         else
         {
-            std::memset(lo, 0, 5);
-            nu_utf8_write(code_point, lo);
-            output.append(lo);
+            output.write(itr, nitr - itr);
         }
     }
-    return output;
-}
 
+    return output.str();
 }
-}
+
+}}