Add error_handler_t::keep to copy invalid UTF-8 bytes unchanged

error_handler_t::ignore drops invalid bytes although its docs promised to copy them (#4552). Add keep, which copies each ill-formed subsequence byte-for-byte while still escaping valid characters.

Fixes #4552

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
This commit is contained in:
Niels Lohmann
2026-09-26 07:37:05 +02:00
parent f422b753cc
commit 8aabb9981f
15 changed files with 283 additions and 13 deletions
+25 -1
View File
@@ -14,6 +14,7 @@
#include <nlohmann/json.hpp>
using nlohmann::json;
#include <algorithm>
#include <fstream>
#include <sstream>
#include <iostream>
@@ -75,8 +76,11 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
static std::string s_replaced2;
static std::string s_replaced_ascii;
static std::string s_replaced2_ascii;
static std::string s_kept;
static std::string s_kept2;
static std::string s_kept_ascii;
// dumping with ignore/replace must not throw in any case
// dumping with ignore/replace/keep must not throw in any case
s_ignored = j.dump(-1, ' ', false, json::error_handler_t::ignore);
s_ignored2 = j2.dump(-1, ' ', false, json::error_handler_t::ignore);
s_ignored_ascii = j.dump(-1, ' ', true, json::error_handler_t::ignore);
@@ -85,6 +89,9 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
s_replaced2 = j2.dump(-1, ' ', false, json::error_handler_t::replace);
s_replaced_ascii = j.dump(-1, ' ', true, json::error_handler_t::replace);
s_replaced2_ascii = j2.dump(-1, ' ', true, json::error_handler_t::replace);
s_kept = j.dump(-1, ' ', false, json::error_handler_t::keep);
s_kept2 = j2.dump(-1, ' ', false, json::error_handler_t::keep);
s_kept_ascii = j.dump(-1, ' ', true, json::error_handler_t::keep);
if (success_expected)
{
@@ -94,6 +101,7 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
// all dumps should agree on the string
CHECK(s_strict == s_ignored);
CHECK(s_strict == s_replaced);
CHECK(s_strict == s_kept);
}
else
{
@@ -105,6 +113,20 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
// check that replace string contains a replacement character
CHECK(s_replaced.find("\xEF\xBF\xBD") != std::string::npos);
// ignore drops the invalid bytes, keep copies them
CHECK(s_ignored != s_kept);
CHECK(s_ignored_ascii != s_kept_ascii);
// unless a byte needs escaping, keep copies the input unchanged
const bool needs_escaping = std::any_of(json_string.begin(), json_string.end(), [](char c)
{
return static_cast<unsigned char>(c) < 0x20 || c == '"' || c == '\\';
});
if (!needs_escaping)
{
CHECK(s_kept == "\"" + json_string + "\"");
}
}
// check that prefix and suffix are preserved
@@ -116,6 +138,8 @@ void check_utf8dump(bool success_expected, int byte1, int byte2 = -1, int byte3
CHECK(s_replaced2.substr(s_replaced2.size() - 4, 3) == "xyz");
CHECK(s_replaced2_ascii.substr(1, 3) == "abc");
CHECK(s_replaced2_ascii.substr(s_replaced2_ascii.size() - 4, 3) == "xyz");
CHECK(s_kept2.substr(1, 3) == "abc");
CHECK(s_kept2.substr(s_kept2.size() - 4, 3) == "xyz");
}
void check_utf8string(bool success_expected, int byte1, int byte2, int byte3, int byte4);