Add support for get QStandardPaths locations.

Inside desktop files we want to reach also data, cache and config home
to create files inside these directories.

REVIEW: 127462
CHANGELOG: Add support for get QStandardPaths locations inside desktop files.

4 files changed, 49 insertions, 0 deletions

diff --git a/autotests/kconfigtest.cpp b/autotests/kconfigtest.cpp
index e92197f3..2b905b57 100644
--- a/autotests/kconfigtest.cpp
+++ b/autotests/kconfigtest.cpp
@@ -552,6 +552,40 @@ void KConfigTest::testPersistenceOfExpandFlagForPath()
     testPath();
 }
 
+void KConfigTest::testPathQtHome()
+{
+    {
+        QFile file(testConfigDir() + "/pathtest");
+        file.open(QIODevice::WriteOnly | QIODevice::Text);
+        QTextStream out(&file);
+        out.setCodec("UTF-8");
+        out << "[Test Group]" << endl
+            << "dataDir[$e]=$QT_DATA_HOME/kconfigtest" << endl
+            << "cacheDir[$e]=$QT_CACHE_HOME/kconfigtest" << endl
+            << "configDir[$e]=$QT_CONFIG_HOME/kconfigtest" << endl;
+    }
+    KConfig cf2(TEST_SUBDIR "pathtest");
+    KConfigGroup group = cf2.group("Test Group");
+    qunsetenv("QT_DATA_HOME");
+    qunsetenv("QT_CACHE_HOME");
+    qunsetenv("QT_CONFIG_HOME");
+    QVERIFY(group.hasKey("dataDir"));
+    QCOMPARE(group.readEntry("dataDir", QString()), QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation).append(QStringLiteral("/kconfigtest")));
+    QVERIFY(group.hasKey("cacheDir"));
+    QCOMPARE(group.readEntry("cacheDir", QString()), QStandardPaths::writableLocation(QStandardPaths::GenericCacheLocation).append(QStringLiteral("/kconfigtest")));
+    QVERIFY(group.hasKey("configDir"));
+    QCOMPARE(group.readEntry("configDir", QString()), QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation).append(QStringLiteral("/kconfigtest")));
+    qputenv("QT_DATA_HOME","/1");
+    qputenv("QT_CACHE_HOME","/2");
+    qputenv("QT_CONFIG_HOME","/3");
+    QVERIFY(group.hasKey("dataDir"));
+    QCOMPARE(group.readEntry("dataDir", QString()), QStringLiteral("/1/kconfigtest"));
+    QVERIFY(group.hasKey("cacheDir"));
+    QCOMPARE(group.readEntry("cacheDir", QString()), QStringLiteral("/2/kconfigtest"));
+    QVERIFY(group.hasKey("configDir"));
+    QCOMPARE(group.readEntry("configDir", QString()), QStringLiteral("/3/kconfigtest"));
+}
+
 void KConfigTest::testComplex()
 {
     KConfig sc2(TEST_SUBDIR "kconfigtest");
diff --git a/autotests/kconfigtest.h b/autotests/kconfigtest.h
index be0a17ea..0a3de477 100644
--- a/autotests/kconfigtest.h
+++ b/autotests/kconfigtest.h
@@ -41,6 +41,7 @@ private Q_SLOTS:
     void testLocale();
     void testEncoding();
     void testPath();
+    void testPathQtHome();
     void testPersistenceOfExpandFlagForPath();
     void testComplex();
     void testEnums();
diff --git a/docs/options.md b/docs/options.md
index c7a6c061..ba7e2d89 100644
--- a/docs/options.md
+++ b/docs/options.md
@@ -90,4 +90,10 @@ The following syntax for environment variables is also supported:
 
     Name[$ei]=${USER}
 
+There are three environment variables that have a fallback strategy if the
+environment variable is not set. They instead map to a location from QStanardPaths.
+They are:
 
+    `$QT_CACHE_HOME` - QStandardPaths::GenericConfigLocation
+    `$QT_CONFIG_HOME` - QStandardPaths::GenericConfigLocation
+    `$QT_DATA_HOME` - QStandardPaths::GenericDataLocation
diff --git a/src/core/kconfig.cpp b/src/core/kconfig.cpp
index 07fa6f55..9f17e579 100644
--- a/src/core/kconfig.cpp
+++ b/src/core/kconfig.cpp
@@ -221,6 +221,14 @@ QString KConfigPrivate::expandString(const QString &value)
                     QByteArray pEnv = qgetenv(aVarName.toLatin1().constData());
                     if (!pEnv.isEmpty()) {
                         env = QString::fromLocal8Bit(pEnv.constData());
+                    } else {
+                        if (aVarName == QStringLiteral("QT_DATA_HOME")) {
+                            env = QStandardPaths::writableLocation(QStandardPaths::GenericDataLocation);
+                        } else if (aVarName == QStringLiteral("QT_CONFIG_HOME")) {
+                            env = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation);
+                        } else if (aVarName == QStringLiteral("QT_CACHE_HOME")) {
+			    env = QStandardPaths::writableLocation(QStandardPaths::GenericCacheLocation);
+                        }
                     }
                 }
                 aValue.replace(nDollarPos, nEndPos - nDollarPos, env);