Description
As the JSON specification defines the floating point format independent of any internationalization by simply using a point for the decimal point separator, while the json_reader uses the locale dependent scanf(...) function, there is obviously a mismatch in the value Interpretation. However it is immediatly clear that this circumstance has only effect for languages that do have a decimal point separator different from point.
Since the often mentioned workaround to temporarily modify the locale is evidently not practicable for multithreaded programs that uses GUI toolkits, I had a look to the fix that is reported for Ubuntu. But the corresponding patch is removed from the code (Compare json_tool.h: We had a sophisticated way, but it did not work in WinCE. @see #9). So I had a further look to the function static inline void fixNumericLocale(char* begin, char* end) in the same file, and would propose the following modification:
--- json_reader.cpp.orig 2016-03-25 12:09:14.000000000 +0100
+++ json_reader.cpp.new 2016-08-08 17:42:40.921538600 +0200
@@ -1619,6 +1619,7 @@
Char buffer[bufferSize + 1];
memcpy(buffer, token.start_, ulength);
buffer[length] = 0;
+ fixNumericLocaleInput(buffer, buffer + length);
count = sscanf(buffer, format, &value);
} else {
JSONCPP_STRING buffer(token.start_, token.end_);
--- json_tool.h.orig 2016-03-25 12:09:14.000000000 +0100
+++ json_tool.h.new 2016-08-09 08:55:09.156182800 +0200
@@ -6,6 +6,8 @@
#ifndef LIB_JSONCPP_JSON_TOOL_H_INCLUDED
#define LIB_JSONCPP_JSON_TOOL_H_INCLUDED
+#include <clocale>
+
/* This header provides common string manipulation support, such as UTF-8,
* portable conversion from/to string...
*
@@ -82,6 +84,18 @@
}
}
+static inline void fixNumericLocaleInput(char* begin, char* end) {
+ struct lconv* lc = localeconv();
+ if ((lc != NULL) && (*(lc->decimal_point) != '.')) {
+ while (begin < end) {
+ if (*begin == '.') {
+ *begin = *(lc->decimal_point);
+ }
+ ++begin;
+ }
+ }
+}
+
} // namespace Json {
#endif // LIB_JSONCPP_JSON_TOOL_H_INCLUDED