3 files changed, 16 insertions, 6 deletions
diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index b5d760926a..049df0311b 100644
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/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;
 }
 
 /*!
diff --git a/src/corelib/plugin/qlibrary_p.h b/src/corelib/plugin/qlibrary_p.h
index 965f1d26bd..82c3cd9791 100644
--- a/src/corelib/plugin/qlibrary_p.h
+++ b/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) {
diff --git a/src/corelib/plugin/qpluginloader.cpp b/src/corelib/plugin/qpluginloader.cpp
index 4ef36afcea..2216c1b908 100644
--- a/src/corelib/plugin/qpluginloader.cpp
+++ b/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.",