Just use the path as the url can have an anchor attached etc...

Fixes the broken topic chooser and keyword resolving.

Reviewed-by: ck

src/plugins/help/helpviewer.cpp

@@ -109,10 +109,11 @@ bool HelpViewer::canOpenPage(const QString &url)
     return !mimeFromUrl(url).isEmpty();
 }
 
-QString HelpViewer::mimeFromUrl(const QString &url)
+QString HelpViewer::mimeFromUrl(const QUrl &url)
 {
-    const int index = url.lastIndexOf(QLatin1Char('.'));
-    const QByteArray &ext = url.mid(index).toUtf8().toLower();
+    const QString &path = url.path();
+    const int index = path.lastIndexOf(QLatin1Char('.'));
+    const QByteArray &ext = path.mid(index).toUtf8().toLower();
 
     const ExtensionMap *e = extensionMap;
     while (e->extension) {

src/plugins/help/helpviewer.h

@@ -91,7 +91,7 @@ public:
 
     static bool isLocalUrl(const QUrl &url);
     static bool canOpenPage(const QString &url);
-    static QString mimeFromUrl(const QString &url);
+    static QString mimeFromUrl(const QUrl &url);
     static bool launchWithExternalApp(const QUrl &url);
 
 public slots: