From 0bee705e4d758465481de6f61e08edaf2dc39dc8 Mon Sep 17 00:00:00 2001
From: M66B <M66B@users.noreply.github.com>
Date: Mon, 8 Jul 2019 11:01:40 +0200
Subject: [PATCH] Improved message decoding

---
 .../eu/faircode/email/FragmentMessages.java   |  2 +-
 .../java/eu/faircode/email/MessageHelper.java | 32 ++++++++-----------
 2 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/app/src/main/java/eu/faircode/email/FragmentMessages.java b/app/src/main/java/eu/faircode/email/FragmentMessages.java
index a82ff2f215..d10ef55490 100644
--- a/app/src/main/java/eu/faircode/email/FragmentMessages.java
+++ b/app/src/main/java/eu/faircode/email/FragmentMessages.java
@@ -3714,7 +3714,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
 
                                 // Remove previously decrypted attachments
                                 for (EntityAttachment local : attachments)
-                                    if (local.encryption == null && !"application/pgp-encrypted".equals(local.type))
+                                    if (local.encryption == null)
                                         db.attachment().deleteAttachment(local.id);
 
                                 int sequence = db.attachment().getAttachmentSequence(id);
diff --git a/app/src/main/java/eu/faircode/email/MessageHelper.java b/app/src/main/java/eu/faircode/email/MessageHelper.java
index ada72edd49..82e0c1887c 100644
--- a/app/src/main/java/eu/faircode/email/MessageHelper.java
+++ b/app/src/main/java/eu/faircode/email/MessageHelper.java
@@ -780,7 +780,6 @@ public class MessageHelper {
         String getHtml(Context context) throws MessagingException, IOException {
             if (plain == null && html == null) {
                 Log.i("No body part");
-                warnings.add(context.getString(R.string.title_no_body));
                 return null;
             }
 
@@ -814,6 +813,7 @@ public class MessageHelper {
             try {
                 ContentType ct = new ContentType(part.getContentType());
                 String charset = ct.getParameter("charset");
+
                 String encoding = null;
                 try {
                     String[] enc = part.getHeader("Content-Transfer-Encoding");
@@ -822,26 +822,24 @@ public class MessageHelper {
                 } catch (MessagingException ex) {
                     Log.w(ex);
                 }
-                if (TextUtils.isEmpty(charset)) {
-                    if (BuildConfig.DEBUG)
-                        warnings.add(context.getString(R.string.title_no_charset, ct));
+
+                if (TextUtils.isEmpty(charset) || "US-ASCII".equals(charset.toUpperCase())) {
                     // The first 127 characters are the same as in US-ASCII
                     result = new String(result.getBytes(StandardCharsets.ISO_8859_1));
+                } else if (encoding != null && "8bit".equals(encoding.toLowerCase()) &&
+                        "ISO-8859-1".equals(charset.toUpperCase())) {
+                    // Workaround JavaMail bug
+                    result = new String(result.getBytes(StandardCharsets.ISO_8859_1));
                 } else {
-                    if ("US-ASCII".equals(charset.toUpperCase()) ||
-                            (encoding != null && "8bit".equals(encoding.toLowerCase()) &&
-                                    "ISO-8859-1".equals(charset.toUpperCase())))
-                        result = new String(result.getBytes(StandardCharsets.ISO_8859_1));
-                    else {
-                        if ("US-ASCII".equals(Charset.forName(charset).name()))
-                            warnings.add(context.getString(R.string.title_no_charset, charset));
-                    }
+                    if ("US-ASCII".equals(Charset.forName(charset).name()))
+                        warnings.add(context.getString(R.string.title_no_charset, charset));
                 }
             } catch (ParseException ex) {
                 Log.w(ex);
                 warnings.add(Helper.formatThrowable(ex, false));
             }
 
+            // Prevent Jsoup throwing an exception
             result = result.replace("\0", "");
 
             if (part.isMimeType("text/plain")) {
@@ -997,10 +995,11 @@ public class MessageHelper {
                 for (int i = 0; i < multipart.getCount(); i++)
                     try {
                         Part cpart = multipart.getBodyPart(i);
-                        getMessageParts(cpart, parts, pgp);
                         ContentType ct = new ContentType(cpart.getContentType());
                         if ("application/pgp-encrypted".equals(ct.getBaseType().toLowerCase()))
                             pgp = true;
+                        else
+                            getMessageParts(cpart, parts, pgp);
                     } catch (ParseException ex) {
                         // Nested body: try to continue
                         // ParseException: In parameter list boundary="...">, expected parameter name, got ";"
@@ -1029,11 +1028,6 @@ public class MessageHelper {
                     filename = null;
                 }
 
-                //Log.i("Part" +
-                //        " disposition=" + disposition +
-                //        " filename=" + filename +
-                //        " content type=" + part.getContentType());
-
                 if (!Part.ATTACHMENT.equalsIgnoreCase(disposition) &&
                         TextUtils.isEmpty(filename) &&
                         ((parts.plain == null && part.isMimeType("text/plain")) ||
@@ -1081,7 +1075,7 @@ public class MessageHelper {
                         apart.attachment.name = "invite.ics";
 
                     // Try to guess a better content type
-                    // Sometimes PDF files are sent using the wrong type
+                    // For example, sometimes PDF files are sent as application/octet-stream
                     if ("application/octet-stream".equalsIgnoreCase(apart.attachment.type)) {
                         String extension = Helper.getExtension(apart.attachment.name);
                         if (extension != null) {