Merge branch 'develop' into claude/issue-5066-24ba30

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

include/nlohmann/detail/input/binary_reader.hpp

@@ -3821,11 +3821,6 @@ class binary_reader
         if (0xC2 <= byte && byte <= 0xF7)
         {
             const auto second = get_bon8();
-            if (second == char_traits<char_type>::eof())
-            {
-                // the input ends inside a character or an integer
-                return unexpect_eof(input_format_t::bon8, "key");
-            }
             unget_bon8(second);
             if (is_bon8_continuation(second))
             {
@@ -3924,12 +3919,6 @@ class binary_reader
             // a lead byte ends the string if no continuation byte follows: it
             // is then the first byte of an integer
             const auto second = get_bon8();
-            if (second == char_traits<char_type>::eof())
-            {
-                // the input ends inside a character or an integer: either
-                // way, the message is incomplete
-                return unexpect_eof(input_format_t::bon8, "string");
-            }
             if (!is_bon8_continuation(second))
             {
                 unget_bon8(second);

single_include/nlohmann/json.hpp

@@ -16588,11 +16588,6 @@ class binary_reader
         if (0xC2 <= byte && byte <= 0xF7)
         {
             const auto second = get_bon8();
-            if (second == char_traits<char_type>::eof())
-            {
-                // the input ends inside a character or an integer
-                return unexpect_eof(input_format_t::bon8, "key");
-            }
             unget_bon8(second);
             if (is_bon8_continuation(second))
             {
@@ -16691,12 +16686,6 @@ class binary_reader
             // a lead byte ends the string if no continuation byte follows: it
             // is then the first byte of an integer
             const auto second = get_bon8();
-            if (second == char_traits<char_type>::eof())
-            {
-                // the input ends inside a character or an integer: either
-                // way, the message is incomplete
-                return unexpect_eof(input_format_t::bon8, "string");
-            }
             if (!is_bon8_continuation(second))
             {
                 unget_bon8(second);

tests/src/unit-bon8.cpp

@@ -531,47 +531,6 @@ TEST_CASE("BON8")
             CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x87, 'a'}), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing BON8 string: unexpected end of input", json::parse_error&);
         }
 
-        SECTION("input that ends after a UTF-8 lead byte")
-        {
-            // the lead byte begins either a character or an integer; both are
-            // incomplete, so the lead byte must not end the string before it
-            for (const bool strict :
-                    {
-                        true, false
-                    })
-            {
-                CAPTURE(strict)
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{'a', 0xC3}, strict), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing BON8 string: unexpected end of input", json::parse_error&);
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x81, 'a', 0xC3}, strict), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BON8 string: unexpected end of input", json::parse_error&);
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x81, 'a', 0xE2}, strict), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BON8 string: unexpected end of input", json::parse_error&);
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x81, 'a', 0xF0}, strict), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BON8 string: unexpected end of input", json::parse_error&);
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x81, 0xC3, 0xA9, 0xC3}, strict), "[json.exception.parse_error.110] parse error at byte 5: syntax error while parsing BON8 string: unexpected end of input", json::parse_error&);
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x87, 'a', 0xC3}, strict), "[json.exception.parse_error.110] parse error at byte 4: syntax error while parsing BON8 string: unexpected end of input", json::parse_error&);
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x87, 0xC3}, strict), "[json.exception.parse_error.110] parse error at byte 3: syntax error while parsing BON8 key: unexpected end of input", json::parse_error&);
-                CHECK_THROWS_WITH_AS(_ = json::from_bon8(bytes{0x88, 'a', 0x91, 0xE2}, strict), "[json.exception.parse_error.110] parse error at byte 5: syntax error while parsing BON8 key: unexpected end of input", json::parse_error&);
-            }
-        }
-
-        SECTION("a message that is cut off is not read as a shorter value")
-        {
-            const json values = {"\xC3\xA9", "a\xE2\x82\xAC", "\xF0\x9F\x98\x80\xC3\xA9", {"a\xC3\xA9"}, {{"\xC3\xA9", "\xE2\x82\xAC"}}, {{"a", {"b\xC3\xA9", 1}}}};
-            for (const auto& j : values)
-            {
-                const bytes message = json::to_bon8(j);
-                for (std::size_t length = 0; length < message.size(); ++length)
-                {
-                    CAPTURE(j)
-                    CAPTURE(length)
-                    bytes prefix = message;
-                    prefix.resize(length);
-                    CHECK(json::from_bon8(prefix, false, false).is_discarded());
-                    // a stream is read byte by byte rather than in bulk
-                    std::istringstream stream(str(prefix));
-                    CHECK(json::from_bon8(stream, false, false).is_discarded());
-                }
-            }
-        }
-
         SECTION("invalid UTF-8")
         {
             // overlong

tests/src/unit-regression2.cpp

@@ -766,6 +766,25 @@ TEST_CASE("regression tests 2")
         CHECK(j == k);
     }
 
+#ifdef JSON_HAS_CPP_17
+    SECTION("issue #5066 - MSVC converts json to std::variant<json> via the conversion operator")
+    {
+        // std::variant<json> must not be retrievable via get<>(), because otherwise the
+        // implicit conversion operator becomes a candidate that MSVC picks over the variant's
+        // converting constructor, routing a number through the string from_json overload
+        static_assert(!nlohmann::detail::is_detected<nlohmann::detail::get_template_function, const json&, std::variant<json>>::value,
+                      "std::variant<json> must not be retrievable via get<>()");
+
+        // clang before 7 cannot instantiate libstdc++'s std::variant<json>
+#if !(defined(__clang__) && __clang_major__ < 7)
+        // push_back, not emplace_back: #5066 needs the implicit conversion
+        // from json to the vector's value type
+        std::vector<std::variant<json>> v;
+        v.push_back(json(1)); // NOLINT(hicpp-use-emplace,modernize-use-emplace)
+        CHECK(std::get<0>(v[0]) == 1);
+#endif
+    }
+#endif
 }
 
 TEST_CASE("regression test - parser callback must not lose a duplicate key's prior value")