[FarGroup/FarManager] master: Generalize DECRQM queries (97b38b7c5)

[farg...@farmanager.com]

Repository : https://github.com/FarGroup/FarManager
On branch : master
Link : https://github.com/FarGroup/FarManager/commit/97b38b7c5e1cdfcb66f3d947629192b717de4b39

>---------------------------------------------------------------

commit 97b38b7c5e1cdfcb66f3d947629192b717de4b39
Author: Alex Alabuzhev <alab...@gmail.com>
Date: Tue Aug 26 22:26:41 2025 +0100

Generalize DECRQM queries


>---------------------------------------------------------------

97b38b7c5e1cdfcb66f3d947629192b717de4b39
far/console.cpp | 106 ++++++++++++++++++++++++++++++++------------------------
1 file changed, 61 insertions(+), 45 deletions(-)

diff --git a/far/console.cpp b/far/console.cpp
index cd66d1615..a2f07605b 100644
--- a/far/console.cpp
+++ b/far/console.cpp
@@ -670,6 +670,56 @@ protected:
}
}

+ static std::optional<wchar_t> decrqm(string_view const Query)
+ {
+ // No need to make noise on legacy systems
+ if (!::console.IsVtSupported())
+ return {};
+
+ try
+ {
+ const auto ResponseData = query_vt(concat(CSI, L'?', Query, L"$p"sv));
+ if (ResponseData.empty())
+ {
+ LOGWARNING(L"DECRQM {} query is not supported"sv, Query);
+ return {};
+ }
+
+ const auto Prefix = concat(CSI, L'?', Query, L';');
+ const auto Suffix = L"$y"sv;
+
+ const auto give_up = [&]
+ {
+ throw far_exception(far::format(L"Incorrect response: {}"sv, ResponseData), false);
+ };
+
+ if (ResponseData.size() != Prefix.size() + 1 + Suffix.size() || !ResponseData.starts_with(Prefix) || !ResponseData.ends_with(Suffix))
+ give_up();
+
+ switch (const auto Char = ResponseData[Prefix.size()])
+ {
+ case L'0':
+ LOGWARNING(L"DECRQM {} query is not supported"sv, Query);
+ return {};
+
+ case L'1':
+ case L'2':
+ case L'3':
+ case L'4':
+ return Char;
+
+ default:
+ give_up();
+ std::unreachable();
+ }
+ }
+ catch (std::exception const& e)
+ {
+ LOGERROR(L"{}"sv, e);
+ return {};
+ }
+ }
+
console::console():
m_OriginalInputHandle(GetStdHandle(STD_INPUT_HANDLE)),
m_StreamBuf(std::make_unique<consolebuf>(GetStdHandle(STD_OUTPUT_HANDLE))),
@@ -3100,56 +3150,22 @@ protected:

std::optional<bool> console::is_grapheme_clusters_on() const
{
- // No need to make noise on legacy systems
- if (!IsVtSupported())
+ const auto Response = decrqm(L"2027"sv);
+ if (!Response)
return {};

- try
+ switch (*Response)
{
-#define DECRQM_REQUEST "?2027"
-
- const auto ResponseData = query_vt(CSI DECRQM_REQUEST "$p"sv);
- if (ResponseData.empty())
- {
- LOGWARNING(L"DECRQM 2027 query is not supported"sv);
- return {};
- }
-
- const auto
- Prefix = CSI DECRQM_REQUEST ";"sv,
- Suffix = L"$y"sv;
-
-#undef DECRQM_REQUEST
-
- const auto give_up = [&]
- {
- throw far_exception(far::format(L"Incorrect response: {}"sv, ResponseData), false);
- };
-
- if (ResponseData.size() != Prefix.size() + 1 + Suffix.size() || !ResponseData.starts_with(Prefix) || !ResponseData.ends_with(Suffix))
- give_up();
-
- switch (ResponseData[Prefix.size()])
- {
- case L'0':
- LOGWARNING(L"DECRQM 2027 query is not supported"sv);
- return {};
-
- case L'1':
- case L'3': return true;
+ case L'1':
+ case L'3':
+ return true;

- case L'2':
- case L'4': return false;
+ case L'2':
+ case L'4':
+ return false;

- default:
- give_up();
- std::unreachable();
- }
- }
- catch (std::exception const& e)
- {
- LOGERROR(L"{}"sv, e);
- return {};
+ default:
+ std::unreachable();
}
}