Finally constify isValid() [BIC]

svn path=/trunk/KDE/kdelibs/; revision=963116

runnercontext.cpp

@@ -307,7 +307,7 @@ QString RunnerContext::mimeType() const
     return d->mimeType;
 }
 
-bool RunnerContext::isValid()
+bool RunnerContext::isValid() const
 {
     // if our qptr is dirty, we aren't useful anymore
     return (d->q != &(d->s_dummyContext));

runnercontext.h

@@ -117,9 +117,10 @@ class PLASMA_EXPORT RunnerContext : public QObject
          *
          * While not required to be used within runners, it provies a nice way
          * to avoid unecessary processing in runners that may run for an extended
-         * period (as measured in 10s of ms) and therefore improve the user experience.
+         * period (as measured in 10s of ms) and therefore improve the user experience. 
+         * @since 4.2.3
          */
-        bool isValid();
+        bool isValid() const;
 
          /**
          * Appends lists of matches to the list of matches.