5 files changed, 42 insertions, 7 deletions
diff --git a/src/corelib/io/qstandardpaths.cpp b/src/corelib/io/qstandardpaths.cpp
index 86d0f7424d..552bb21972 100644
--- a/src/corelib/io/qstandardpaths.cpp
+++ b/src/corelib/io/qstandardpaths.cpp
@@ -85,6 +85,8 @@ QT_BEGIN_NAMESPACE
            non-essential (cached) data should be written.
     \value GenericDataLocation Returns a directory location where persistent
            data shared across applications can be stored.
+    \value RuntimeLocation Returns a directory location where runtime communication
+           files should be written. For instance unix local sockets.
     \value ConfigLocation Returns a directory location where user-specific
            configuration files should be written.
 
@@ -118,8 +120,6 @@ QT_BEGIN_NAMESPACE
    starting with the user-specific storageLocation() for the \a type.
  */
 
-// TODO add XDG_RUNTIME_DIR?
-
 /*!
     \enum QStandardPaths::LocateOption
 
diff --git a/src/corelib/io/qstandardpaths.h b/src/corelib/io/qstandardpaths.h
index d0293ab3fd..ac2a17ddc8 100644
--- a/src/corelib/io/qstandardpaths.h
+++ b/src/corelib/io/qstandardpaths.h
@@ -71,6 +71,7 @@ public:
         DataLocation,
         CacheLocation,
         GenericDataLocation,
+        RuntimeLocation,
         ConfigLocation
     };
 
diff --git a/src/corelib/io/qstandardpaths_mac.cpp b/src/corelib/io/qstandardpaths_mac.cpp
index a13162cc7b..4f379fac09 100644
--- a/src/corelib/io/qstandardpaths_mac.cpp
+++ b/src/corelib/io/qstandardpaths_mac.cpp
@@ -77,6 +77,7 @@ OSType translateLocation(QStandardPaths::StandardLocation type)
     case QStandardPaths::TempLocation:
         return kTemporaryFolderType;
     case QStandardPaths::GenericDataLocation:
+    case QStandardPaths::RuntimeLocation:
     case QStandardPaths::DataLocation:
         return kApplicationSupportFolderType;
     case QStandardPaths::CacheLocation:
@@ -126,6 +127,7 @@ QString QStandardPaths::storageLocation(StandardLocation type)
     case GenericDataLocation:
     case DataLocation:
     case CacheLocation:
+    case RuntimeLocation:
         return macLocation(type, kUserDomain);
     default:
         return macLocation(type, kOnAppropriateDisk);
diff --git a/src/corelib/io/qstandardpaths_unix.cpp b/src/corelib/io/qstandardpaths_unix.cpp
index 5a52c2518f..12f872f5fa 100644
--- a/src/corelib/io/qstandardpaths_unix.cpp
+++ b/src/corelib/io/qstandardpaths_unix.cpp
@@ -46,6 +46,8 @@
 #include <qfile.h>
 #include <qtextstream.h>
 #include <qcoreapplication.h>
+#include <private/qfilesystemengine_p.h>
+#include <errno.h>
 #include <stdlib.h>
 
 #ifndef QT_NO_STANDARDPATHS
@@ -93,6 +95,38 @@ QString QStandardPaths::storageLocation(StandardLocation type)
             xdgConfigHome = QDir::homePath() + QLatin1String("/.config");
         return xdgConfigHome;
     }
+    case RuntimeLocation:
+    {
+        const uid_t myUid = geteuid();
+        // http://standards.freedesktop.org/basedir-spec/latest/
+        QString xdgRuntimeDir = QFile::decodeName(qgetenv("XDG_RUNTIME_DIR"));
+        if (xdgRuntimeDir.isEmpty()) {
+            const QString userName = QFileSystemEngine::resolveUserName(myUid);
+            xdgRuntimeDir = QDir::tempPath() + QLatin1String("/runtime-") + userName;
+            QDir dir(xdgRuntimeDir);
+            if (!dir.exists()) {
+                if (!QDir().mkdir(xdgRuntimeDir)) {
+                    qWarning("QStandardPaths: error creating runtime directory %s: %s", qPrintable(xdgRuntimeDir), qPrintable(qt_error_string(errno)));
+                    return QString();
+                }
+            }
+        }
+        // "The directory MUST be owned by the user"
+        QFileInfo fileInfo(xdgRuntimeDir);
+        if (fileInfo.ownerId() != myUid) {
+            qWarning("QStandardPaths: wrong ownership on runtime directory %s, %d instead of %d", qPrintable(xdgRuntimeDir),
+                     fileInfo.ownerId(), myUid);
+            return QString();
+        }
+        // "and he MUST be the only one having read and write access to it. Its Unix access mode MUST be 0700."
+        QFile file(xdgRuntimeDir);
+        const QFile::Permissions wantedPerms = QFile::ReadUser | QFile::WriteUser | QFile::ExeUser;
+        if (file.permissions() != wantedPerms && !file.setPermissions(wantedPerms)) {
+            qWarning("QStandardPaths: wrong permissions on runtime directory %s", qPrintable(xdgRuntimeDir));
+            return QString();
+        }
+        return xdgRuntimeDir;
+    }
     default:
         break;
     }
diff --git a/src/corelib/io/qstandardpaths_win.cpp b/src/corelib/io/qstandardpaths_win.cpp
index 497e09e0e2..bd327e6f37 100644
--- a/src/corelib/io/qstandardpaths_win.cpp
+++ b/src/corelib/io/qstandardpaths_win.cpp
@@ -159,16 +159,14 @@ QString QStandardPaths::storageLocation(StandardLocation type)
         // cache directory located in their AppData directory
         return storageLocation(DataLocation) + QLatin1String("\\cache");
 
-    case QStandardPaths::HomeLocation:
+    case RuntimeLocation:
+    case HomeLocation:
         result = QDir::homePath();
         break;
 
-    case QStandardPaths::TempLocation:
+    case TempLocation:
         result = QDir::tempPath();
         break;
-
-    default:
-        break;
     }
     return result;
 }