fix: open file as binary-mode #16

to avoid inconsistency between file size (obtained by tellg) and the
size of the actual contents that would be read later

README.md

@@ -42,8 +42,14 @@ In the case of file open error, it will throw `std::runtime_error`.
 
 You can also pass a `stream` to the  `toml::parse` function after checking the status.
 
+Note that on __Windows OS__, stream that is opened as text-mode automatically converts
+CRLF ("\r\n") into LF ("\n") and this leads inconsistency between file size and
+the contents that would be read. This causes weird error. To use a file stream
+with `toml::parse`, don't forget to pass binary mode flag when you open the
+stream.
+
 ```cpp
-std::ifstream ifs("sample.toml");
+std::ifstream ifs("sample.toml", std::ios_base::binary);
 assert(ifs.good());
 const auto data = toml::parse(ifs /*, "filename" (optional)*/);
 ```

tests/test_parse_file.cpp

@@ -213,6 +213,20 @@ BOOST_AUTO_TEST_CASE(test_file_with_BOM)
         BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
         BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
     }
+    {
+        const std::string table(
+            "\xEF\xBB\xBF" // BOM
+            "key = \"value\"\n"
+            "[table]\n"
+            "key = \"value\"\n"
+            );
+        std::ofstream ofs("tmp.toml");
+        ofs << table;
+        const auto data = toml::parse("tmp.toml");
+
+        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
+        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+    }
     {
         const std::string table(
             "\xEF\xBB\xBF" // BOM
@@ -223,6 +237,20 @@ BOOST_AUTO_TEST_CASE(test_file_with_BOM)
         std::istringstream iss(table);
         const auto data = toml::parse(iss, "test_file_with_BOM_CRLF.toml");
 
+        BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
+        BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
+    }
+    {
+        const std::string table(
+            "\xEF\xBB\xBF" // BOM
+            "key = \"value\"\r\n"
+            "[table]\r\n"
+            "key = \"value\"\r\n"
+            );
+        std::ofstream ofs("tmp.toml");
+        ofs << table;
+        const auto data = toml::parse("tmp.toml");
+
         BOOST_CHECK_EQUAL(toml::get <std::string>(data.at("key")), "value");
         BOOST_CHECK_EQUAL(toml::find<std::string>(data.at("table"), "key"), "value");
     }

toml/parser.hpp

@@ -1517,7 +1517,7 @@ inline table parse(std::istream& is, std::string fname = "unknown file")
 
 inline table parse(const std::string& fname)
 {
-    std::ifstream ifs(fname.c_str());
+    std::ifstream ifs(fname.c_str(), std::ios_base::binary);
     if(!ifs.good())
     {
         throw std::runtime_error("toml::parse: file open error -> " + fname);