diff --git a/include/fmt/core.h b/include/fmt/core.h index 5135f1f9..7a0e8b89 100644 --- a/include/fmt/core.h +++ b/include/fmt/core.h @@ -761,7 +761,7 @@ class fixed_buffer_traits { explicit fixed_buffer_traits(size_t limit) : limit_(limit) {} size_t count() const { return count_; } size_t limit(size_t size) { - size_t n = limit_ - count_; + size_t n = limit_ > count_ ? limit_ - count_ : 0; count_ += size; return size < n ? size : n; } diff --git a/test/format-test.cc b/test/format-test.cc index d3f21b47..c995ff69 100644 --- a/test/format-test.cc +++ b/test/format-test.cc @@ -1967,6 +1967,11 @@ TEST(FormatTest, FormatToN) { result = fmt::format_to_n(buffer, 4, "{}", "ABCDE"); EXPECT_EQ(5u, result.size); EXPECT_EQ("ABCD", fmt::string_view(buffer, 4)); + + buffer[3] = 'x'; + result = fmt::format_to_n(buffer, 3, "{}", std::string(1000, '*')); + EXPECT_EQ(1000u, result.size); + EXPECT_EQ("***x", fmt::string_view(buffer, 4)); } TEST(FormatTest, WideFormatToN) {