Added idle restart for Outlook

app/src/main/java/com/sun/mail/imap/IMAPFolder.java

@@ -16,6 +16,8 @@
 
 package com.sun.mail.imap;
 
+import android.os.SystemClock;
+
 import java.util.Date;
 import java.util.Vector;
 import java.util.Hashtable;
@@ -3284,6 +3286,8 @@ public class IMAPFolder extends Folder implements UIDFolder, ResponseHandler {
      */
     boolean handleIdle(boolean once) throws MessagingException {
 	Response r = null;
+	long start = SystemClock.elapsedRealtime();
+	long restartIdleInterval = ((IMAPStore)store).getRestartIdleInterval() * 1000L;
 	do {
 	    r = protocol.readIdleResponse();
 	    try {
@@ -3304,6 +3308,12 @@ public class IMAPFolder extends Folder implements UIDFolder, ResponseHandler {
 				logger.finest(
 				    "handleIdle: ignoring socket timeout");
 				r = null;	// repeat do/while loop
+				long elapsed = SystemClock.elapsedRealtime() - start;
+				if (restartIdleInterval > 0 && elapsed > restartIdleInterval) {
+					logger.finest("handleIdle: restart elapsed=" + elapsed);
+					protocol.idleAbort();
+					idleState = ABORTING;
+				}
 			    } else {
 				logger.finest("handleIdle: interrupting IDLE");
 				IdleManager im = idleManager;

app/src/main/java/com/sun/mail/imap/IMAPStore.java

@@ -175,6 +175,8 @@ public class IMAPStore extends Store
 
     private final int minIdleTime;	// minimum idle time
 
+    private final int restartIdleInterval;
+
     private volatile int port = -1;	// port to use
 
     // Auth info
@@ -477,6 +479,9 @@ public class IMAPStore extends Store
 	if (logger.isLoggable(Level.CONFIG))
 	    logger.config("mail.imap.minidletime: " + minIdleTime);
 
+	restartIdleInterval = PropUtil.getIntProperty(props,
+	    "mail." + name + ".restartidleinterval", 0);
+
 	// check if we should do a PROXYAUTH login
 	String s = session.getProperty("mail." + name + ".proxyauth.user");
 	if (s != null) {
@@ -1579,6 +1584,10 @@ public class IMAPStore extends Store
 	return minIdleTime;
     }
 
+	int getRestartIdleInterval() {
+	return restartIdleInterval;
+	}
+
     /**
      * Throw a SearchException if the search expression is too complex?
      */

app/src/main/java/eu/faircode/email/EmailService.java

@@ -329,6 +329,10 @@ public class EmailService implements AutoCloseable {
         properties.put("mail." + protocol + ".allow8bitmime", Boolean.toString(value));
     }
 
+    void setRestartIdleInterval(int seconds) {
+        properties.put("mail." + protocol + ".restartidleinterval", Integer.toString(seconds));
+    }
+
     // https://tools.ietf.org/html/rfc3461
     void setDsnNotify(String what) {
         properties.put("mail." + protocol + ".dsn.notify", what);

app/src/main/java/eu/faircode/email/ServiceSynchronize.java

@@ -1518,6 +1518,11 @@ public class ServiceSynchronize extends ServiceBase implements SharedPreferences
                 if (account.protocol != EntityAccount.TYPE_IMAP)
                     iservice.setLeaveOnServer(account.leave_on_server);
 
+                if ("outlook.office365.com".equalsIgnoreCase(account.host)) {
+                    int timeout = prefs.getInt("timeout", EmailService.DEFAULT_CONNECT_TIMEOUT);
+                    iservice.setRestartIdleInterval(timeout * 2 * 6); // 20 x 2 x 6 = 4 min
+                }
+
                 final Date lastStillHere = new Date(0);
 
                 iservice.setListener(new StoreListener() {