From 6e41104426a3ae59bcb90be708abcc3092155436 Mon Sep 17 00:00:00 2001
From: Andreas Cord-Landwehr <cordlandwehr@kde.org>
Date: Tue, 24 Aug 2021 21:06:47 +0200
Subject: [PATCH] Fix automatic currency file sync after 24h

Conversion plugin in Krunner depends on automatic refresh of currency
table. std::call_once does not work there, because process is never
stopped.

BUG: 441337
---
 autotests/convertertest.cpp | 16 ++++++++++++++++
 autotests/convertertest.h   |  6 ++++++
 src/currency.cpp            |  9 ++++++---
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/autotests/convertertest.cpp b/autotests/convertertest.cpp
index aa0ccae..e36b7fe 100644
--- a/autotests/convertertest.cpp
+++ b/autotests/convertertest.cpp
@@ -8,9 +8,11 @@
 #include <QStandardPaths>
 #include <QThread>
 #include <QVector>
+#include <currency_p.h>
 #include <kunitconversion/unitcategory.h>
 
 using namespace KUnitConversion;
+using namespace std::chrono_literals;
 
 void ConverterTest::initTestCase()
 {
@@ -113,4 +115,18 @@ void ConverterTest::testCurrency()
     qDeleteAll(threads);
 }
 
+void ConverterTest::testCurrencyConversionTableUpdate()
+{
+    const QString cache = QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation) + QStringLiteral("/libkunitconversion/currency.xml");
+
+    // Missing conversion table must lead to update of table
+    // note that this is the same code path as for last modified updates
+    QFile::remove(cache);
+    QVERIFY(Currency::lastConversionTableUpdate().isNull());
+    Converter c;
+    Value input = Value(1000, Eur);
+    Value v = c.convert(input, QStringLiteral("$"));
+    QVERIFY(!Currency::lastConversionTableUpdate().isNull());
+}
+
 QTEST_MAIN(ConverterTest)
diff --git a/autotests/convertertest.h b/autotests/convertertest.h
index 21d5213..d3d6303 100644
--- a/autotests/convertertest.h
+++ b/autotests/convertertest.h
@@ -23,6 +23,12 @@ private Q_SLOTS:
     void testConvert();
     void testInvalid();
     void testCurrency();
+    /**
+     * Checks that conversion tables are updated after timeout
+     *
+     * Regression test for https://bugs.kde.org/show_bug.cgi?id=441337
+     */
+    void testCurrencyConversionTableUpdate();
 };
 
 #endif // CONVERTERTEST_H
diff --git a/src/currency.cpp b/src/currency.cpp
index 038e928..ead7ce5 100644
--- a/src/currency.cpp
+++ b/src/currency.cpp
@@ -745,9 +745,12 @@ void CurrencyCategoryPrivate::syncConversionTable(std::chrono::seconds updateSki
 Value CurrencyCategoryPrivate::convert(const Value &value, const Unit &to)
 {
     // TODO KF6 remove this blocking call and change behavior that explicit call to syncConversionTable is mandatory before
-    // right now, if a sync is performed at application start, then this call will not block anymore for 24 hours
-    static std::once_flag updateFlag;
-    std::call_once(updateFlag, &CurrencyCategoryPrivate::syncConversionTable, this, 24h);
+    // first access to converted data, also to make syncs more explicit
+    static QMutex updateFlag;
+    {
+        QMutexLocker locker(&updateFlag);
+        CurrencyCategoryPrivate::syncConversionTable(24h);
+    }
 
     Value v = UnitCategoryPrivate::convert(value, to);
     return v;
-- 
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