fixed some bugs for romeo

Romeo/src/JsonParser.cpp

@@ -431,15 +431,19 @@ namespace Romeo
         Assert(arena != nullptr);
         
         size_t escLen = 0;
-        const char* p = CStr(str);
-        const char* end = p + str.Size;
+        const unsigned char* p = reinterpret_cast<const unsigned char*>(CStr(str));
+        const unsigned char* end = p + str.Size;
         while (p < end)
         {
-            char c = *p;
-            if (c == '"' || c == '\\' || c == '\n' || c == '\r' || c == '\t')
+            unsigned char c = *p;
+            if (c == '"' || c == '\\' || c == '\n' || c == '\r' || c == '\t' || c == '\b' || c == '\f')
             {
                 escLen += 2;
             }
+            else if (c < 32)
+            {
+                escLen += 6;
+            }
             else
             {
                 escLen += 1;
@@ -449,16 +453,23 @@ namespace Romeo
         
         char* buf = Juliet::ArenaPushArray<char>(arena, escLen + 1 JULIET_DEBUG_PARAM("JsonEscapedStr"));
         char* dst = buf;
-        p = CStr(str);
+        p = reinterpret_cast<const unsigned char*>(CStr(str));
         while (p < end)
         {
-            char c = *p;
+            unsigned char c = *p;
             if (c == '"') { *dst++ = '\\'; *dst++ = '"'; }
             else if (c == '\\') { *dst++ = '\\'; *dst++ = '\\'; }
             else if (c == '\n') { *dst++ = '\\'; *dst++ = 'n'; }
             else if (c == '\r') { *dst++ = '\\'; *dst++ = 'r'; }
             else if (c == '\t') { *dst++ = '\\'; *dst++ = 't'; }
-            else { *dst++ = c; }
+            else if (c == '\b') { *dst++ = '\\'; *dst++ = 'b'; }
+            else if (c == '\f') { *dst++ = '\\'; *dst++ = 'f'; }
+            else if (c < 32)
+            {
+                snprintf(dst, 7, "\\u00%02x", static_cast<unsigned int>(c));
+                dst += 6;
+            }
+            else { *dst++ = static_cast<char>(c); }
             p++;
         }
         *dst = '\0';