From f22bc3f540c9664fd90e6675b39174ec8d3f6b1c Mon Sep 17 00:00:00 2001
From: askmeaboutloom <askmeaboutlo0m@users.noreply.github.com>
Date: Tue, 12 Nov 2024 15:18:24 +0100
Subject: [PATCH] Reset locale to "C" on Unix systems

After Qt messes it up when you initialze a QCoreApplication or similar.
---
 ChangeLog                                      |  1 +
 src/desktop/main.cpp                           |  2 ++
 src/drawdance/libcommon/dpcommon/platform_qt.h | 14 ++++++++++++++
 src/thinsrv/main.cpp                           |  3 ++-
 src/tools/drawpile-timelapse/main.cpp          |  1 +
 5 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 0ff05ec665..7dc9acd3ba 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,7 @@ Unreleased Version 2.2.2-pre
  * Fix: Make temporary tool switches by holding a key down work again. Thanks 3rd_EFNO and bunnie for reporting.
  * Fix: Disregard hidden layers when layer picking in frame view.
  * Feature: Add a search bar to the key frame properties dialog.
+ * Fix: Reset locale to "C" after Qt messes it up on startup. Thanks Meru for reporting.
 
 2024-11-06 Version 2.2.2-beta.4
  * Fix: Solve rendering glitches with selection outlines that happen on some systems. Thanks xxxx for reporting.
diff --git a/src/desktop/main.cpp b/src/desktop/main.cpp
index 7449533be9..2af2ffad95 100644
--- a/src/desktop/main.cpp
+++ b/src/desktop/main.cpp
@@ -9,6 +9,7 @@
 #include "desktop/utils/globalkeyeventfilter.h"
 #include "desktop/utils/qtguicompat.h"
 #include "desktop/utils/recents.h"
+#include "dpcommon/platform_qt.h"
 #include "libclient/brushes/brushpresetmodel.h"
 #include "libclient/drawdance/global.h"
 #include "libclient/utils/colorscheme.h"
@@ -1125,6 +1126,7 @@ extern "C" void drawpileMain(int argc, char **argv)
 	DrawpileApp appInstance(argc, argv);
 	DrawpileApp *app = &appInstance;
 #endif
+	DP_QT_LOCALE_RESET();
 
 	compat::disableImageReaderAllocationLimit();
 	startApplication(app);
diff --git a/src/drawdance/libcommon/dpcommon/platform_qt.h b/src/drawdance/libcommon/dpcommon/platform_qt.h
index f43371c16e..62c901441a 100644
--- a/src/drawdance/libcommon/dpcommon/platform_qt.h
+++ b/src/drawdance/libcommon/dpcommon/platform_qt.h
@@ -3,6 +3,20 @@
 #define DPCOMMON_PLATFORM_H
 #include <QIODevice>
 
+// On Unix systems, Qt messes up the locale on startup.
+#ifdef Q_OS_UNIX
+#    include <locale.h>
+#    define DP_QT_LOCALE_RESET()    \
+        do {                        \
+            setlocale(LC_ALL, "C"); \
+        } while (0)
+#else
+#    define DP_QT_LOCALE_RESET() \
+        do {                     \
+            /* nothing */        \
+        } while (0)
+#endif
+
 // On Android, files don't get truncated when writing without the truncate flag.
 static constexpr QIODevice::OpenMode DP_QT_WRITE_FLAGS =
 #ifdef Q_OS_ANDROID
diff --git a/src/thinsrv/main.cpp b/src/thinsrv/main.cpp
index 30f1c64a38..80f268214c 100644
--- a/src/thinsrv/main.cpp
+++ b/src/thinsrv/main.cpp
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 #include "cmake-config/config.h"
+#include "dpcommon/platform_qt.h"
 #include "libserver/jsonapi.h" // for datatype registration
 #include "thinsrv/headless/headless.h"
 #include "thinsrv/initsys.h"
@@ -56,7 +57,7 @@ int main(int argc, char *argv[])
 #else
 	app.reset(new QCoreApplication(argc, argv));
 #endif
-
+	DP_QT_LOCALE_RESET();
 
 	// Set common settings
 	QCoreApplication::setOrganizationName("drawpile");
diff --git a/src/tools/drawpile-timelapse/main.cpp b/src/tools/drawpile-timelapse/main.cpp
index 681ea92dae..36416ceb9b 100644
--- a/src/tools/drawpile-timelapse/main.cpp
+++ b/src/tools/drawpile-timelapse/main.cpp
@@ -51,6 +51,7 @@ static QString writeDefaultLogo()
 int main(int argc, char **argv)
 {
 	QCoreApplication app(argc, argv);
+	DP_QT_LOCALE_RESET();
 	app.setOrganizationName("drawpile");
 	app.setOrganizationDomain("drawpile.net");
 	app.setApplicationName("drawpile-timelapse");