Improved type guessing

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

@@ -26,7 +26,6 @@ import android.os.Bundle;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.webkit.MimeTypeMap;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.ProgressBar;
@@ -110,7 +109,7 @@ public class AdapterAttachment extends RecyclerView.Adapter<AdapterAttachment.Vi
             ibDelete.setVisibility(readonly ? View.GONE : View.VISIBLE);
 
             int resid = 0;
-            String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(attachment.getMimeType());
+            String extension = Helper.guessExtension(attachment.getMimeType());
             if (extension != null)
                 resid = context.getResources().getIdentifier("file_" + extension, "drawable", context.getPackageName());
             if (resid == 0)

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

@@ -22,7 +22,6 @@ package eu.faircode.email;
 import android.content.Context;
 import android.os.Build;
 import android.text.TextUtils;
-import android.webkit.MimeTypeMap;
 
 import androidx.annotation.NonNull;
 import androidx.room.Entity;
@@ -35,7 +34,6 @@ import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
-import java.util.Locale;
 import java.util.Objects;
 
 import javax.mail.Part;
@@ -173,26 +171,7 @@ public class EntityAttachment {
         if (extension == null)
             return type;
 
-        String gtype = MimeTypeMap.getSingleton()
-                .getMimeTypeFromExtension(extension.toLowerCase(Locale.ROOT));
-
-        if (gtype != null) {
-            if (TextUtils.isEmpty(type) || "*/*".equals(type))
-                type = gtype;
-
-            // Some servers erroneously remove dots from mime types
-            if (gtype.replace(".", "").equals(type))
-                type = gtype;
-        }
-
-        if ("csv".equals(extension))
-            return "text/csv";
-
-        if ("eml".equals(extension))
-            return "message/rfc822";
-
-        if ("gpx".equals(extension))
-            return "application/gpx+xml";
+        // Fix types
 
         if ("text/plain".equals(type) && "ics".equals(extension))
             return "text/calendar";
@@ -211,17 +190,20 @@ public class EntityAttachment {
         if ("application/vnd.ms-pps".equals(type))
             return "application/vnd.ms-powerpoint";
 
-        if (TextUtils.isEmpty(type) ||
-                type.startsWith("unknown/") || type.endsWith("/unknown") ||
-                "application/octet-stream".equals(type) || "application/zip".equals(type)) {
-            if ("log".equalsIgnoreCase(extension))
-                return "text/plain";
+        // Guess types
+        String gtype = Helper.guessMimeType(name);
+        if (gtype != null) {
+            if (TextUtils.isEmpty(type) ||
+                    "*/*".equals(type) ||
+                    type.startsWith("unknown/") ||
+                    type.endsWith("/unknown") ||
+                    "application/octet-stream".equals(type) ||
+                    "application/zip".equals(type))
+                return gtype;
 
-            if (gtype == null || gtype.equals(type))
-                return type;
-
-            Log.w("Guessing file=" + name + " type=" + gtype);
-            return gtype;
+            // Some servers erroneously remove dots from mime types
+            if (gtype.replace(".", "").equals(type))
+                return gtype;
         }
 
         return type;

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

@@ -2879,7 +2879,9 @@ public class FragmentCompose extends FragmentBase {
                 ftype = null;
             }
 
-        if (TextUtils.isEmpty(ftype) || "*/*".equals(ftype))
+        if (TextUtils.isEmpty(ftype) ||
+                "*/*".equals(ftype) ||
+                "application/octet-stream".equals(ftype))
             ftype = Helper.guessMimeType(fname);
 
         if (fsize != null && fsize <= 0)

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

@@ -941,16 +941,50 @@ public class Helper {
         String type = null;
 
         String extension = Helper.getExtension(filename);
-        if (extension != null)
+        if (extension != null) {
+            extension = extension.toLowerCase(Locale.ROOT);
             type = MimeTypeMap.getSingleton()
                     .getMimeTypeFromExtension(extension.toLowerCase(Locale.ROOT));
+        }
 
         if (TextUtils.isEmpty(type))
-            type = "application/octet-stream";
+            if ("csv".equals(extension))
+                return "text/csv";
+            else if ("eml".equals(extension))
+                return "message/rfc822";
+            else if ("gpx".equals(extension))
+                return "application/gpx+xml";
+            else if ("log".equals(extension))
+                return "text/plain";
+            else if ("ovpn".equals(extension))
+                return "application/x-openvpn-profile";
+            else
+                return "application/octet-stream";
 
         return type;
     }
 
+    static String guessExtension(String mimeType) {
+        String extension = null;
+
+        if (mimeType != null) {
+            mimeType = mimeType.toLowerCase(Locale.ROOT);
+            extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mimeType);
+        }
+
+        if (TextUtils.isEmpty(extension))
+            if ("text/csv".equals(mimeType))
+                return "csv";
+            else if ("message/rfc822".equals(mimeType))
+                return "eml";
+            else if ("application/gpx+xml".equals(mimeType))
+                return "gpx";
+            else if ("application/x-openvpn-profile".equals(mimeType))
+                return "ovpn";
+
+        return extension;
+    }
+
     static void writeText(File file, String content) throws IOException {
         try (FileOutputStream out = new FileOutputStream(file)) {
             if (content != null)