WebDAV: use RetryDuration property as timeout interval

The RetryDuration value now defines the time after which the Neon
library is told to give up. Previously some Neon-internal default
was used.

Resending a pending request earlier still needs to be implemented.
As with SyncML over HTTP, a loss of network connectivity can lead
to a half-open TCP connection which the client cannot detect when
relying on TCP alone.

src/backends/webdav/NeonCXX.cpp

@@ -201,6 +201,13 @@ Session::Session(const boost::shared_ptr<Settings> &settings) :
         URI proxyuri = URI::parse(m_proxyURL);
         ne_session_proxy(m_session, proxyuri.m_host.c_str(), proxyuri.m_port);
     }
+
+    int seconds = settings->timeoutSeconds();
+    if (seconds < 0) {
+        seconds = 5 * 60;
+    }
+    ne_set_read_timeout(m_session, seconds);
+    ne_set_connect_timeout(m_session, seconds);
 }
 
 Session::~Session()

src/backends/webdav/NeonCXX.h

@@ -90,6 +90,12 @@ class Settings {
      */
     virtual bool googleAlarmHack() const = 0;
 
+    /**
+     * duration in seconds after which communication with a server
+     * fails with a timeout error; <= 0 picks a large default value
+     */
+    virtual int timeoutSeconds() const = 0;
+
     /**
      * use this to create a boost_shared pointer for a
      * Settings instance which needs to be freed differently

src/backends/webdav/WebDAVSource.cpp

@@ -109,6 +109,12 @@ public:
     virtual bool googleChildHack() const { return m_googleChildHack; }
     virtual bool googleAlarmHack() const { return m_googleChildHack; }
 
+    /**
+     * Communication is aborted after the configured retry duration.
+     * TODO: resend after retryInterval() seconds.
+     */
+    virtual int timeoutSeconds() const { return m_context->getRetryDuration(); }
+
     virtual void getCredentials(const std::string &realm,
                                 std::string &username,
                                 std::string &password)