Plugin metadata is now updated in setFileName(), not load().

Plugin metadata has been updated in load(), with the
side-effect of metadata not beeing available until
plugin has been loaded - and which the new metadata
system tries to prevent in the first place. The
metadata is now updated (and avaiable) as soon as
a valid filename is set.

Change-Id: Ia5aedc67d8115e71c2ecbcbcadf786ba1c2893d8
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

src/corelib/plugin/qlibrary.cpp

@@ -580,12 +580,19 @@ bool qt_get_metadata(QtPluginQueryVerificationDataFunction pfn, QLibraryPrivate
     return true;
 }
 
-
 bool QLibraryPrivate::isPlugin()
+{
+    if (pluginState == MightBeAPlugin)
+        updatePluginState();
+
+    return pluginState == IsAPlugin;
+}
+
+void QLibraryPrivate::updatePluginState()
 {
     errorString.clear();
     if (pluginState != MightBeAPlugin)
-        return pluginState == IsAPlugin;
+        return;
 
     bool success = false;
 
@@ -599,7 +606,7 @@ bool QLibraryPrivate::isPlugin()
         // pretend we didn't see the file
         errorString = QLibrary::tr("The shared library was not found.");
         pluginState = IsNotAPlugin;
-        return false;
+        return;
     }
 #endif
 
@@ -687,7 +694,8 @@ bool QLibraryPrivate::isPlugin()
             else
                 errorString = QLibrary::tr("The file '%1' is not a valid Qt plugin.").arg(fileName);
         }
-        return false;
+        pluginState = IsNotAPlugin;
+        return;
     }
 
     pluginState = IsNotAPlugin; // be pessimistic
@@ -717,8 +725,6 @@ bool QLibraryPrivate::isPlugin()
     } else {
         pluginState = IsAPlugin;
     }
-
-    return pluginState == IsAPlugin;
 }
 
 /*!

src/corelib/plugin/qlibrary_p.h

@@ -103,6 +103,7 @@ public:
     QString errorString;
     QLibrary::LoadHints loadHints;
 
+    void updatePluginState();
     bool isPlugin();
 
     static inline QJsonDocument fromRawMetaData(const char *raw) {

src/corelib/plugin/qpluginloader.cpp

@@ -283,6 +283,9 @@ void QPluginLoader::setFileName(const QString &fileName)
     d->loadHints = lh;
     if (fn.isEmpty())
         d->errorString = QLibrary::tr("The shared library was not found.");
+    else
+        d->updatePluginState();
+
 #else
     if (qt_debug_component()) {
         qWarning("Cannot load %s into a statically linked Qt library.",