Improved body structure workaround

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

@@ -574,15 +574,23 @@ public class IMAPMessage extends MimeMessage implements ReadableMime {
 	if (type == null) {
 	    loadBODYSTRUCTURE();
 
-		// Some servers report incorrectly text/plain in some situations
-		if ("text".equalsIgnoreCase(bs.type) &&
-				"plain".equalsIgnoreCase(bs.subtype))
+		// Some servers, like Yandex, report an incorrect/incomplete BODYSTRUCTURE
+		if (("text".equalsIgnoreCase(bs.type) &&
+				"plain".equalsIgnoreCase(bs.subtype)) ||
+				("multipart".equalsIgnoreCase(bs.type) &&
+						("signed".equalsIgnoreCase(bs.subtype) || "encrypted".equalsIgnoreCase(bs.subtype)) &&
+						(bs.cParams == null || bs.cParams.get("protocol") == null)) ||
+				("application".equalsIgnoreCase(bs.type) &&
+						("pkcs7-mime".equalsIgnoreCase(bs.subtype) || "x-pkcs7-mime".equalsIgnoreCase(bs.subtype)) &&
+						(bs.cParams == null || bs.cParams.get("smime-type") == null)))
 			try {
-				String[] c = getHeader("Content-type");
+				String[] c = getHeader("Content-type"); // Fetches header
 				if (c != null && c.length == 1) {
 					ContentType ct = new ContentType(c[0]);
-					if (!bs.type.equalsIgnoreCase(ct.getPrimaryType()) ||
-							!bs.subtype.equalsIgnoreCase(ct.getSubType())) {
+					if (!("text".equalsIgnoreCase(bs.type) &&
+							"plain".equalsIgnoreCase(bs.subtype)) ||
+							!(bs.type.equalsIgnoreCase(ct.getPrimaryType()) &&
+									bs.subtype.equalsIgnoreCase(ct.getSubType()))) {
 						eu.faircode.email.Log.e("Inconsistent" +
 								" bs=" + bs.type + "/" + bs.subtype + "/" + bs.cParams + " header=" + ct);
 						type = ct.toString();

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

@@ -2645,32 +2645,9 @@ public class MessageHelper {
 
         try {
             if (imessage instanceof IMAPMessage) {
-                if (structure) {
-                    String contentType = imessage.getContentType(); // force loadBODYSTRUCTURE
-
-                    // Workaround protocol parameter missing
-                    // Happens with Yandex and possibly other providers
-                    boolean load = false;
-                    try {
-                        ContentType ct = new ContentType(contentType);
-                        if (ct.match("multipart/signed") || ct.match("multipart/encrypted")) {
-                            String protocol = ct.getParameter("protocol");
-                            if (protocol == null)
-                                load = true;
-                        } else if (ct.match("application/pkcs7-mime") || ct.match("application/x-pkcs7-mime")) {
-                            String smimeType = ct.getParameter("smime-type");
-                            if (smimeType == null)
-                                load = true;
-                        }
-                    } catch (Throwable ex) {
-                        Log.w(ex);
-                    }
-
-                    if (load) {
-                        Log.w("Protocol missing content-type=" + contentType);
-                        throw new MessagingException("Failed to load IMAP envelope");
-                    }
-                } else {
+                if (structure)
+                    imessage.getContentType(); // force loadBODYSTRUCTURE
+                else {
                     if (headers)
                         imessage.getAllHeaders(); // force loadHeaders
                     else