Remove a Network::Exception that isn't one.

Code smell pointed out by Coverity.

src/frontend/stmclient.cc

@@ -539,15 +539,16 @@ bool STMClient::main( void )
 
       network->tick();
 
-      const Network::NetworkException *exn = network->get_send_exception();
-      if ( exn ) {
-        overlays.get_notification_engine().set_network_exception( *exn );
+      string & send_error = network->get_send_error();
+      if ( !send_error.empty() ) {
+        overlays.get_notification_engine().set_network_error( send_error );
+	send_error.clear();
       } else {
-        overlays.get_notification_engine().clear_network_exception();
+        overlays.get_notification_engine().clear_network_error();
       }
     } catch ( const Network::NetworkException &e ) {
       if ( !network->shutdown_in_progress() ) {
-        overlays.get_notification_engine().set_network_exception( e );
+        overlays.get_notification_engine().set_network_error( e.what() );
       }
 
       struct timespec req;

src/frontend/terminaloverlay.cc

@@ -168,7 +168,7 @@ NotificationEngine::NotificationEngine()
     last_acked_state( timestamp() ),
     escape_key_string(),
     message(),
-    message_is_network_exception( false ),
+    message_is_network_error( false ),
     message_expiration( -1 ),
     show_quit_keystroke( true )
 {}

src/frontend/terminaloverlay.h

@@ -40,7 +40,6 @@
 
 #include <vector>
 #include <limits.h>
-#include <exception>
 
 namespace Overlay {
   using namespace Terminal;
@@ -147,7 +146,7 @@ namespace Overlay {
     uint64_t last_acked_state;
     string escape_key_string;
     wstring message;
-    bool message_is_network_exception;
+    bool message_is_network_error;
     uint64_t message_expiration;
     bool show_quit_keystroke;
 
@@ -171,7 +170,7 @@ namespace Overlay {
       } else {
         message_expiration = timestamp() + 1000;
       }
-      message_is_network_exception = false;
+      message_is_network_error = false;
       show_quit_keystroke = s_show_quit_keystroke;
     }
 
@@ -182,19 +181,19 @@ namespace Overlay {
       escape_key_string = tmp;
     }
 
-    void set_network_exception( const std::exception &e )
+    void set_network_error( const std::string &s )
     {
       wchar_t tmp[ 128 ];
-      swprintf( tmp, 128, L"%s", e.what() );
+      swprintf( tmp, 128, L"%s", s.c_str() );
 
       message = tmp;
-      message_is_network_exception = true;
+      message_is_network_error = true;
       message_expiration = timestamp() + Network::ACK_INTERVAL + 100;
     }
 
-    void clear_network_exception()
+    void clear_network_error()
     {
-      if ( message_is_network_exception ) {
+      if ( message_is_network_error ) {
 	message_expiration = std::min( message_expiration, timestamp() + 1000 );
       }
     }

src/network/network.cc

@@ -249,8 +249,7 @@ Connection::Connection( const char *desired_ip, const char *desired_port ) /* se
     RTT_hit( false ),
     SRTT( 1000 ),
     RTTVAR( 500 ),
-    have_send_exception( false ),
-    send_exception()
+    send_error()
 {
   setup();
 
@@ -369,8 +368,7 @@ Connection::Connection( const char *key_str, const char *ip, const char *port )
     RTT_hit( false ),
     SRTT( 1000 ),
     RTTVAR( 500 ),
-    have_send_exception( false ),
-    send_exception()
+    send_error()
 {
   setup();
 
@@ -405,14 +403,10 @@ void Connection::send( const string & s )
   ssize_t bytes_sent = sendto( sock(), p.data(), p.size(), MSG_DONTWAIT,
 			       &remote_addr.sa, remote_addr_len );
 
-  if ( bytes_sent == static_cast<ssize_t>( p.size() ) ) {
-    have_send_exception = false;
-  } else {
-    /* Notify the frontend on sendto() failure, but don't alter control flow.
-       sendto() success is not very meaningful because packets can be lost in
-       flight anyway. */
-    have_send_exception = true;
-    send_exception = NetworkException( "sendto", errno );
+  if ( bytes_sent != static_cast<ssize_t>( p.size() ) ) {
+    /* Make sendto() failure available to the frontend. */
+    send_error = "sendto: ";
+    send_error += strerror( errno );
 
     if ( errno == EMSGSIZE ) {
       MTU = DEFAULT_SEND_MTU; /* payload MTU of last resort */

src/network/network.h

@@ -187,10 +187,8 @@ namespace Network {
     double SRTT;
     double RTTVAR;
 
-    /* Exception from send(), to be delivered if the frontend asks for it,
-       without altering control flow. */
-    bool have_send_exception;
-    NetworkException send_exception;
+    /* Error from send()/sendto(). */
+    string send_error;
 
     Packet new_packet( const string &s_payload );
 
@@ -226,9 +224,9 @@ namespace Network {
     const Addr &get_remote_addr( void ) const { return remote_addr; }
     socklen_t get_remote_addr_len( void ) const { return remote_addr_len; }
 
-    const NetworkException *get_send_exception( void ) const
+    string &get_send_error( void )
     {
-      return have_send_exception ? &send_exception : NULL;
+      return send_error;
     }
 
     void set_last_roundtrip_success( uint64_t s_success ) { last_roundtrip_success = s_success; }

src/network/networktransport.h

@@ -119,7 +119,7 @@ namespace Network {
     const Addr &get_remote_addr( void ) const { return connection.get_remote_addr(); }
     socklen_t get_remote_addr_len( void ) const { return connection.get_remote_addr_len(); }
 
-    const NetworkException *get_send_exception( void ) const { return connection.get_send_exception(); }
+    std::string &get_send_error( void ) { return connection.get_send_error(); }
   };
 }