cppcheck performance: function parameter should be passed by reference

cppcheck found some minor cases where complex parameters were accidentally
passed by value.

src/backends/webdav/WebDAVSource.cpp

@@ -93,7 +93,7 @@ public:
         }
     }
 
-    void setURL(const std::string url) { initializeFlags(url); m_url = url; }
+    void setURL(const std::string &url) { initializeFlags(url); m_url = url; }
     virtual std::string getURL() { return m_url; }
 
     virtual bool verifySSLHost()

src/dbus/server/pim/filtered-view.cpp

@@ -78,7 +78,7 @@ void FilteredView::doStart()
     m_parent->m_removedSignal.connect(ChangeSignal_t::slot_type(boost::bind(&FilteredView::removeIndividual, this, _1, _2)).track(m_self));
 }
 
-bool FilteredView::isFull(const Entries_t local2parent,
+bool FilteredView::isFull(const Entries_t &local2parent,
                           const boost::shared_ptr<IndividualFilter> &filter)
 {
     size_t newEndIndex = local2parent.end() - local2parent.begin();

src/dbus/server/pim/filtered-view.h

@@ -49,7 +49,7 @@ class FilteredView : public IndividualView
     void init(const boost::shared_ptr<FilteredView> &self);
 
     bool isFull() const { return isFull(m_local2parent, m_filter); }
-    static bool isFull(const Entries_t local2parent,
+    static bool isFull(const Entries_t &local2parent,
                        const boost::shared_ptr<IndividualFilter> &filter);
 
     /**

src/dbus/server/session.h

@@ -386,7 +386,7 @@ public:
      * the sync starts and overwriting it when the connection
      * closes.
      */
-    void setStubConnectionError(const std::string error) { m_connectionError = error; }
+    void setStubConnectionError(const std::string &error) { m_connectionError = error; }
     std::string getStubConnectionError() { return m_connectionError; }
 
     Server &getServer() { return m_server; }

src/syncevo/Cmdline.cpp

@@ -110,7 +110,7 @@ bool Cmdline::parse()
 /**
  * Detects "--sync foo", "--sync=foo", "-s foo".
  */
-static bool IsKeyword(const std::string arg,
+static bool IsKeyword(const std::string &arg,
                       const char *longWord,
                       const char *shortWord)
 {

src/syncevo/SyncContext.cpp

@@ -1106,7 +1106,7 @@ private:
     string m_previousLogdir; /**< remember previous log dir before creating the new one */
 
     /** create name in current (if set) or previous logdir */
-    string databaseName(SyncSource &source, const string suffix, string logdir = "") {
+    string databaseName(SyncSource &source, const string &suffix, string logdir = "") {
         if (!logdir.size()) {
             logdir = m_logdir->getLogdir();
         }