Fix QDesktopServices::storageLocation() when registry keys are missing

We should not use the registry key when looking up the storage
location as this is not really supported by Microsoft and not
allways accessible. Instead we now use SHGetSpecialFolderPath.
Note that we avoid SHGetKnownFolderPath as it is not available
on all CE platforms though it is the reccommended function by
Microsoft.

Task-number: QTBUG-3241
Reviewed-by: prasanth

1 files changed, 44 insertions, 22 deletions

diff --git a/src/gui/util/qdesktopservices_win.cpp b/src/gui/util/qdesktopservices_win.cpp
index 9ae3a15..bf29870 100644
--- a/src/gui/util/qdesktopservices_win.cpp
+++ b/src/gui/util/qdesktopservices_win.cpp
@@ -41,6 +41,7 @@
 
 #include <qsettings.h>
 #include <qdir.h>
+#include <qlibrary.h>
 #include <qurl.h>
 #include <qstringlist.h>
 #include <qprocess.h>
@@ -168,50 +169,72 @@ static bool launchWebBrowser(const QUrl &url)
 
 QString QDesktopServices::storageLocation(StandardLocation type)
 {
-#if !defined(QT_NO_SETTINGS)	
-    QSettings settings(QSettings::UserScope, QLatin1String("Microsoft"), QLatin1String("Windows"));
-    settings.beginGroup(QLatin1String("CurrentVersion/Explorer/Shell Folders"));
+    QString result;
+
+#ifndef Q_OS_WINCE
+        QLibrary library(QLatin1String("shell32"));
+#else
+        QLibrary library(QLatin1String("coredll"));
+#endif // Q_OS_WINCE
+    typedef BOOL (WINAPI*GetSpecialFolderPath)(HWND, LPWSTR, int, BOOL);
+    static GetSpecialFolderPath SHGetSpecialFolderPath =
+            (GetSpecialFolderPath)library.resolve("SHGetSpecialFolderPathW");
+    if (!SHGetSpecialFolderPath)
+        return QString();
+
+    wchar_t path[MAX_PATH];
+
     switch (type) {
-    case CacheLocation:
-        // Although Microsoft has a Cache key it is a pointer to IE's cache, not a cache
-        // location for everyone.  Most applications seem to be using a
-        // cache directory located in their AppData directory
-        return storageLocation(DataLocation) + QLatin1String("\\cache");
     case DataLocation:
-        if (!settings.contains(QLatin1String("Local AppData")))
-            break;
-        return settings.value(QLatin1String("Local AppData")).toString()
-            + QLatin1String("\\") + QCoreApplication::organizationName()
-            + QLatin1String("\\") + QCoreApplication::applicationName();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_LOCAL_APPDATA, FALSE))
+            result = QString::fromWCharArray(path);
+        if (!QCoreApplication::organizationName().isEmpty())
+            result = result + QLatin1String("\\") + QCoreApplication::organizationName();
+        if (!QCoreApplication::applicationName().isEmpty())
+            result = result + QLatin1String("\\") + QCoreApplication::applicationName();
         break;
+
     case DesktopLocation:
-        return settings.value(QLatin1String("Desktop")).toString();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_DESKTOPDIRECTORY, FALSE))
+            result = QString::fromWCharArray(path);
         break;
 
     case DocumentsLocation:
-        return settings.value(QLatin1String("Personal")).toString();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_PERSONAL, FALSE))
+            result = QString::fromWCharArray(path);
         break;
 
     case FontsLocation:
-        return settings.value(QLatin1String("Fonts")).toString();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_FONTS, FALSE))
+            result = QString::fromWCharArray(path);
         break;
 
     case ApplicationsLocation:
-        return settings.value(QLatin1String("Programs")).toString();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_PROGRAMS, FALSE))
+            result = QString::fromWCharArray(path);
         break;
 
     case MusicLocation:
-        return settings.value(QLatin1String("My Music")).toString();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_MYMUSIC, FALSE))
+            result = QString::fromWCharArray(path);
         break;
 
     case MoviesLocation:
-        return settings.value(QLatin1String("My Video")).toString();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_MYVIDEO, FALSE))
+            result = QString::fromWCharArray(path);
         break;
 
     case PicturesLocation:
-        return settings.value(QLatin1String("My Pictures")).toString();
+        if (SHGetSpecialFolderPath(0, path, CSIDL_MYPICTURES, FALSE))
+            result = QString::fromWCharArray(path);
         break;
 
+    case CacheLocation:
+        // Although Microsoft has a Cache key it is a pointer to IE's cache, not a cache
+        // location for everyone.  Most applications seem to be using a
+        // cache directory located in their AppData directory
+        return storageLocation(DataLocation) + QLatin1String("\\cache");
+
     case QDesktopServices::HomeLocation:
         return QDir::homePath(); break;
 
@@ -221,8 +244,7 @@ QString QDesktopServices::storageLocation(StandardLocation type)
     default:
         break;
     }
-#endif
-    return QString();
+    return result;
 }
 
 QString QDesktopServices::displayName(StandardLocation type)