ensure direct exit after calling back

any structures may be invalid after callback invocation.

this has the side effect that the socket write callback now returns
void, like all other callbacks do.

src/drv_imap.c

@@ -335,7 +335,7 @@ cmd_submittable( imap_store_t *ctx, struct imap_cmd *cmd )
 	       ctx->num_in_progress < ((imap_store_conf_t *)ctx->gen.conf)->server->max_in_progress;
 }
 
-static int
+static void
 flush_imap_cmds( imap_store_t *ctx )
 {
 	struct imap_cmd *cmd;
@@ -345,7 +345,6 @@ flush_imap_cmds( imap_store_t *ctx )
 			ctx->pending_append = &ctx->pending;
 		send_imap_cmd( ctx, cmd );
 	}
-	return 0;
 }
 
 static void
@@ -1589,7 +1588,7 @@ imap_open_store( store_conf_t *conf, const char *label,
 
 	socket_init( &ctx->conn, &srvc->sconf,
 	             (void (*)( void * ))imap_invoke_bad_callback,
-	             imap_socket_read, (int (*)(void *))flush_imap_cmds, ctx );
+	             imap_socket_read, (void (*)(void *))flush_imap_cmds, ctx );
 	socket_connect( &ctx->conn, imap_open_store_connected );
 }
 

src/socket.c

@@ -80,7 +80,7 @@ ssl_return( const char *func, conn_t *conn, int ret )
 				/* Callers take the short path out, so signal higher layers from here. */
 				conn->state = SCK_EOF;
 				conn->read_callback( conn->callback_aux );
-				return 0;
+				return -1;
 			}
 			sys_error( "Socket error: secure %s %s", func, conn->name );
 		} else {
@@ -766,7 +766,8 @@ do_queued_write( conn_t *conn )
 		conf_wakeup( &conn->ssl_fake, 0 );
 #endif
 	conn->writing = 0;
-	return conn->write_callback( conn->callback_aux );
+	conn->write_callback( conn->callback_aux );
+	return -1;
 }
 
 static void

src/socket.h

@@ -88,7 +88,7 @@ typedef struct {
 
 	void (*bad_callback)( void *aux ); /* async fail while sending or listening */
 	void (*read_callback)( void *aux ); /* data available for reading */
-	int (*write_callback)( void *aux ); /* all *queued* data was sent */
+	void (*write_callback)( void *aux ); /* all *queued* data was sent */
 	union {
 		void (*connect)( int ok, void *aux );
 		void (*starttls)( int ok, void *aux );
@@ -123,7 +123,7 @@ static INLINE void socket_init( conn_t *conn,
                                 const server_conf_t *conf,
                                 void (*bad_callback)( void *aux ),
                                 void (*read_callback)( void *aux ),
-                                int (*write_callback)( void *aux ),
+                                void (*write_callback)( void *aux ),
                                 void *aux )
 {
 	conn->conf = conf;