2 files changed, 28 insertions, 0 deletions
diff --git a/src/main/java/eu/siacs/conversations/utils/DNSHelper.java b/src/main/java/eu/siacs/conversations/utils/DNSHelper.java
index 1568eb8c..9caa53f7 100644
--- a/src/main/java/eu/siacs/conversations/utils/DNSHelper.java
+++ b/src/main/java/eu/siacs/conversations/utils/DNSHelper.java
@@ -135,6 +135,7 @@ public class DNSHelper {
         Logging.d("dns", "using dns server: " + dnsServerHostAddress + " to look up " + qname);
         try {
             DNSMessage message = client.query(qname, TYPE.SRV, CLASS.IN, dnsServerHostAddress);
+            if (null != message) {
                 Record[] rrset = message.getAnswers();
                 for (Record rr : rrset) {
                     Data d = rr.getPayload();
@@ -144,6 +145,10 @@ public class DNSHelper {
                         result.add(srvRecord);
                     }
                 }
+            } else {
+                Logging.e("dns", "No valid DNS message retrieved.");
+            }
+
         } catch (IOException e) {
             Logging.d("dns", "Error while retrieving SRV record '" + qname + "' for '" + host + "' from DNS '" + dnsServerHostAddress + "': " + e.getMessage());
         }
diff --git a/src/main/java/eu/siacs/conversations/utils/FileUtils.java b/src/main/java/eu/siacs/conversations/utils/FileUtils.java
index 1f2a71ca..18014894 100644
--- a/src/main/java/eu/siacs/conversations/utils/FileUtils.java
+++ b/src/main/java/eu/siacs/conversations/utils/FileUtils.java
@@ -17,6 +17,8 @@ import java.util.List;
 
 import de.thedevstack.conversationsplus.ConversationsPlusApplication;
 
+import eu.siacs.conversations.entities.Transferable;
+
 public final class FileUtils {
 
 	/**
@@ -160,6 +162,27 @@ public final class FileUtils {
 		return "com.android.providers.media.documents".equals(uri.getAuthority());
 	}
 
+    public static String getRelevantExtension(String path) {
+        if (path == null || path.isEmpty()) {
+            return null;
+        }
+
+        String filename = path.substring(path.lastIndexOf('/') + 1).toLowerCase();
+
+        final String lastPart = FileUtils.getLastExtension(filename);
+
+        if (!lastPart.isEmpty()) {
+            // we want the real file extension, not the crypto one
+            final String secondToLastPart = FileUtils.getSecondToLastExtension(filename);
+            if (!secondToLastPart.isEmpty() && Transferable.VALID_CRYPTO_EXTENSIONS.contains(lastPart)) {
+                return secondToLastPart;
+            } else {
+                return lastPart;
+            }
+        }
+        return null;
+    }
+
 	/**
 	 * @param filename The filename to extract extension from
 	 * @return last extension or empty string