changed mime type handling

7 files changed, 555 insertions, 54 deletions

diff --git a/src/main/java/eu/siacs/conversations/crypto/PgpEngine.java b/src/main/java/eu/siacs/conversations/crypto/PgpEngine.java
index 32b9b9242..cba80ba0b 100644
--- a/src/main/java/eu/siacs/conversations/crypto/PgpEngine.java
+++ b/src/main/java/eu/siacs/conversations/crypto/PgpEngine.java
@@ -59,7 +59,7 @@ public class PgpEngine {
 								message.setEncryption(Message.ENCRYPTION_DECRYPTED);
 								final HttpConnectionManager manager = mXmppConnectionService.getHttpConnectionManager();
 								if (message.trusted()
-										&& message.treatAsDownloadable() == Message.Decision.YES
+										&& message.treatAsDownloadable() != Message.Decision.NEVER
 										&& manager.getAutoAcceptFileSize() > 0) {
 									manager.createNewConnection(message);
 								}
diff --git a/src/main/java/eu/siacs/conversations/entities/DownloadableFile.java b/src/main/java/eu/siacs/conversations/entities/DownloadableFile.java
index 7c8f95d14..ae9ba1f1d 100644
--- a/src/main/java/eu/siacs/conversations/entities/DownloadableFile.java
+++ b/src/main/java/eu/siacs/conversations/entities/DownloadableFile.java
@@ -20,6 +20,8 @@ import javax.crypto.spec.IvParameterSpec;
 import javax.crypto.spec.SecretKeySpec;
 
 import eu.siacs.conversations.Config;
+import eu.siacs.conversations.utils.MimeUtils;
+
 import android.util.Log;
 
 public class DownloadableFile extends File {
@@ -56,16 +58,11 @@ public class DownloadableFile extends File {
 
 	public String getMimeType() {
 		String path = this.getAbsolutePath();
-		try {
-			String mime = URLConnection.guessContentTypeFromName(path.replace("#",""));
-			if (mime != null) {
-				return mime;
-			} else if (mime == null && path.endsWith(".webp")) {
-				return "image/webp";
-			} else {
-				return "";
-			}
-		} catch (final StringIndexOutOfBoundsException e) {
+		int start = path.lastIndexOf('.') + 1;
+		if (start < path.length()) {
+			String mime = MimeUtils.guessMimeTypeFromExtension(path.substring(start));
+			return mime == null ? "" : mime;
+		} else {
 			return "";
 		}
 	}
diff --git a/src/main/java/eu/siacs/conversations/entities/Message.java b/src/main/java/eu/siacs/conversations/entities/Message.java
index 1f622bf4f..0b9386399 100644
--- a/src/main/java/eu/siacs/conversations/entities/Message.java
+++ b/src/main/java/eu/siacs/conversations/entities/Message.java
@@ -9,6 +9,7 @@ import java.util.Arrays;
 
 import eu.siacs.conversations.Config;
 import eu.siacs.conversations.utils.GeoHelper;
+import eu.siacs.conversations.utils.MimeUtils;
 import eu.siacs.conversations.utils.UIHelper;
 import eu.siacs.conversations.xmpp.jid.InvalidJidException;
 import eu.siacs.conversations.xmpp.jid.Jid;
@@ -375,8 +376,8 @@ public class Message extends AbstractEntity {
 						(message.getTimeSent() - this.getTimeSent()) <= (Config.MESSAGE_MERGE_WINDOW * 1000) &&
 						!GeoHelper.isGeoUri(message.getBody()) &&
 						!GeoHelper.isGeoUri(this.body) &&
-						message.treatAsDownloadable() == Decision.NO &&
-						this.treatAsDownloadable() == Decision.NO &&
+						message.treatAsDownloadable() == Decision.NEVER &&
+						this.treatAsDownloadable() == Decision.NEVER &&
 						!message.getBody().startsWith(ME_COMMAND) &&
 						!this.getBody().startsWith(ME_COMMAND) &&
 						!this.bodyIsHeart() &&
@@ -435,49 +436,75 @@ public class Message extends AbstractEntity {
 	}
 
 	public enum Decision {
-		YES,
-		NO,
-		ASK
+		MUST,
+		SHOULD,
+		NEVER,
+	}
+
+	private static String extractRelevantExtension(URL url) {
+		String path = url.getPath();
+		if (path == null || path.isEmpty()) {
+			return null;
+		}
+		String filename = path.substring(path.lastIndexOf('/') + 1).toLowerCase();
+		String[] extensionParts = filename.split("\\.");
+		if (extensionParts.length == 2) {
+			return extensionParts[extensionParts.length - 1];
+		} else if (extensionParts.length == 3 && Arrays
+				.asList(Downloadable.VALID_CRYPTO_EXTENSIONS)
+				.contains(extensionParts[extensionParts.length - 1])) {
+			return extensionParts[extensionParts.length -2];
+		}
+		return null;
+	}
+
+	public String getMimeType() {
+		if (relativeFilePath != null) {
+			int start = relativeFilePath.lastIndexOf('.') + 1;
+			if (start < relativeFilePath.length()) {
+				return MimeUtils.guessMimeTypeFromExtension(relativeFilePath.substring(start));
+			} else {
+				return null;
+			}
+		} else {
+			try {
+				return MimeUtils.guessExtensionFromMimeType(extractRelevantExtension(new URL(body.trim())));
+			} catch (MalformedURLException e) {
+				return null;
+			}
+		}
 	}
 
 	public Decision treatAsDownloadable() {
 		if (body.trim().contains(" ")) {
-			return Decision.NO;
+			return Decision.NEVER;
 		}
 		try {
 			URL url = new URL(body);
 			if (!url.getProtocol().equalsIgnoreCase("http") && !url.getProtocol().equalsIgnoreCase("https")) {
-				return Decision.NO;
+				return Decision.NEVER;
 			}
-			String path = url.getPath();
-			if (path == null || path.isEmpty()) {
-				return Decision.NO;
+			String extension = extractRelevantExtension(url);
+			if (extension == null) {
+				return Decision.NEVER;
 			}
-
-			String filename = path.substring(path.lastIndexOf('/') + 1).toLowerCase();
-			String[] extensionParts = filename.split("\\.");
-			String extension;
 			String ref = url.getRef();
-			if (extensionParts.length == 2) {
-				extension = extensionParts[extensionParts.length - 1];
-			} else if (extensionParts.length == 3 && Arrays
-					.asList(Downloadable.VALID_CRYPTO_EXTENSIONS)
-					.contains(extensionParts[extensionParts.length - 1])) {
-				extension = extensionParts[extensionParts.length -2];
-			} else {
-				return Decision.NO;
-			}
+			boolean encrypted = ref != null && ref.matches("([A-Fa-f0-9]{2}){48}");
 
-			if (Arrays.asList(Downloadable.VALID_IMAGE_EXTENSIONS).contains(extension)) {
-				return Decision.YES;
-			} else if (ref != null && ref.matches("([A-Fa-f0-9]{2}){48}")) {
-				return Decision.ASK;
+			if (encrypted) {
+				if (MimeUtils.guessMimeTypeFromExtension(extension) != null) {
+					return Decision.MUST;
+				} else {
+					return Decision.NEVER;
+				}
+			} else if (Arrays.asList(Downloadable.VALID_IMAGE_EXTENSIONS).contains(extension)) {
+				return Decision.SHOULD;
 			} else {
-				return Decision.NO;
+				return Decision.NEVER;
 			}
 
 		} catch (MalformedURLException e) {
-			return Decision.NO;
+			return Decision.NEVER;
 		}
 	}
 
diff --git a/src/main/java/eu/siacs/conversations/parser/MessageParser.java b/src/main/java/eu/siacs/conversations/parser/MessageParser.java
index 6d2aebf26..d1b8c03ae 100644
--- a/src/main/java/eu/siacs/conversations/parser/MessageParser.java
+++ b/src/main/java/eu/siacs/conversations/parser/MessageParser.java
@@ -360,7 +360,7 @@ public class MessageParser extends AbstractParser implements
 				mXmppConnectionService.databaseBackend.createMessage(message);
 			}
 			final HttpConnectionManager manager = this.mXmppConnectionService.getHttpConnectionManager();
-			if (message.trusted() && message.treatAsDownloadable() == Message.Decision.YES && manager.getAutoAcceptFileSize() > 0) {
+			if (message.trusted() && message.treatAsDownloadable() != Message.Decision.NEVER && manager.getAutoAcceptFileSize() > 0) {
 				manager.createNewConnection(message);
 			} else if (!message.isRead()) {
 				mXmppConnectionService.getNotificationService().push(message);
diff --git a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
index 445aaa474..a04033358 100644
--- a/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
+++ b/src/main/java/eu/siacs/conversations/ui/ConversationFragment.java
@@ -457,7 +457,7 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 			}
 			if (m.getType() != Message.TYPE_TEXT
 					|| m.getDownloadable() != null
-					|| m.treatAsDownloadable() == Message.Decision.NO) {
+					|| m.treatAsDownloadable() == Message.Decision.NEVER) {
 				downloadImage.setVisible(false);
 			}
 			if (!((m.getDownloadable() != null && !(m.getDownloadable() instanceof DownloadablePlaceholder))
@@ -505,8 +505,7 @@ public class ConversationFragment extends Fragment implements EditMessage.Keyboa
 					activity.xmppConnectionService.getFileBackend()
 							.getJingleFileUri(message));
 			shareIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
-			String path = message.getRelativeFilePath();
-			String mime = path == null ? null : URLConnection.guessContentTypeFromName(path);
+			String mime = message.getMimeType();
 			if (mime == null) {
 				mime = "image/webp";
 			}
diff --git a/src/main/java/eu/siacs/conversations/utils/MimeUtils.java b/src/main/java/eu/siacs/conversations/utils/MimeUtils.java
new file mode 100644
index 000000000..a9e89d1b7
--- /dev/null
+++ b/src/main/java/eu/siacs/conversations/utils/MimeUtils.java
@@ -0,0 +1,487 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package eu.siacs.conversations.utils;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+/**
+ * Utilities for dealing with MIME types.
+ * Used to implement java.net.URLConnection and android.webkit.MimeTypeMap.
+ */
+public final class MimeUtils {
+    private static final Map<String, String> mimeTypeToExtensionMap = new HashMap<String, String>();
+    private static final Map<String, String> extensionToMimeTypeMap = new HashMap<String, String>();
+    static {
+        // The following table is based on /etc/mime.types data minus
+        // chemical/* MIME types and MIME types that don't map to any
+        // file extensions. We also exclude top-level domain names to
+        // deal with cases like:
+        //
+        // mail.google.com/a/google.com
+        //
+        // and "active" MIME types (due to potential security issues).
+        // Note that this list is _not_ in alphabetical order and must not be sorted.
+        // The "most popular" extension must come first, so that it's the one returned
+        // by guessExtensionFromMimeType.
+        add("application/andrew-inset", "ez");
+        add("application/dsptype", "tsp");
+        add("application/hta", "hta");
+        add("application/mac-binhex40", "hqx");
+        add("application/mathematica", "nb");
+        add("application/msaccess", "mdb");
+        add("application/oda", "oda");
+        add("application/ogg", "ogg");
+        add("application/ogg", "oga");
+        add("application/pdf", "pdf");
+        add("application/pgp-keys", "key");
+        add("application/pgp-signature", "pgp");
+        add("application/pics-rules", "prf");
+        add("application/pkix-cert", "cer");
+        add("application/rar", "rar");
+        add("application/rdf+xml", "rdf");
+        add("application/rss+xml", "rss");
+        add("application/zip", "zip");
+        add("application/vnd.android.package-archive", "apk");
+        add("application/vnd.cinderella", "cdy");
+        add("application/vnd.ms-pki.stl", "stl");
+        add("application/vnd.oasis.opendocument.database", "odb");
+        add("application/vnd.oasis.opendocument.formula", "odf");
+        add("application/vnd.oasis.opendocument.graphics", "odg");
+        add("application/vnd.oasis.opendocument.graphics-template", "otg");
+        add("application/vnd.oasis.opendocument.image", "odi");
+        add("application/vnd.oasis.opendocument.spreadsheet", "ods");
+        add("application/vnd.oasis.opendocument.spreadsheet-template", "ots");
+        add("application/vnd.oasis.opendocument.text", "odt");
+        add("application/vnd.oasis.opendocument.text-master", "odm");
+        add("application/vnd.oasis.opendocument.text-template", "ott");
+        add("application/vnd.oasis.opendocument.text-web", "oth");
+        add("application/vnd.google-earth.kml+xml", "kml");
+        add("application/vnd.google-earth.kmz", "kmz");
+        add("application/msword", "doc");
+        add("application/msword", "dot");
+        add("application/vnd.openxmlformats-officedocument.wordprocessingml.document", "docx");
+        add("application/vnd.openxmlformats-officedocument.wordprocessingml.template", "dotx");
+        add("application/vnd.ms-excel", "xls");
+        add("application/vnd.ms-excel", "xlt");
+        add("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "xlsx");
+        add("application/vnd.openxmlformats-officedocument.spreadsheetml.template", "xltx");
+        add("application/vnd.ms-powerpoint", "ppt");
+        add("application/vnd.ms-powerpoint", "pot");
+        add("application/vnd.ms-powerpoint", "pps");
+        add("application/vnd.openxmlformats-officedocument.presentationml.presentation", "pptx");
+        add("application/vnd.openxmlformats-officedocument.presentationml.template", "potx");
+        add("application/vnd.openxmlformats-officedocument.presentationml.slideshow", "ppsx");
+        add("application/vnd.rim.cod", "cod");
+        add("application/vnd.smaf", "mmf");
+        add("application/vnd.stardivision.calc", "sdc");
+        add("application/vnd.stardivision.draw", "sda");
+        add("application/vnd.stardivision.impress", "sdd");
+        add("application/vnd.stardivision.impress", "sdp");
+        add("application/vnd.stardivision.math", "smf");
+        add("application/vnd.stardivision.writer", "sdw");
+        add("application/vnd.stardivision.writer", "vor");
+        add("application/vnd.stardivision.writer-global", "sgl");
+        add("application/vnd.sun.xml.calc", "sxc");
+        add("application/vnd.sun.xml.calc.template", "stc");
+        add("application/vnd.sun.xml.draw", "sxd");
+        add("application/vnd.sun.xml.draw.template", "std");
+        add("application/vnd.sun.xml.impress", "sxi");
+        add("application/vnd.sun.xml.impress.template", "sti");
+        add("application/vnd.sun.xml.math", "sxm");
+        add("application/vnd.sun.xml.writer", "sxw");
+        add("application/vnd.sun.xml.writer.global", "sxg");
+        add("application/vnd.sun.xml.writer.template", "stw");
+        add("application/vnd.visio", "vsd");
+        add("application/x-abiword", "abw");
+        add("application/x-apple-diskimage", "dmg");
+        add("application/x-bcpio", "bcpio");
+        add("application/x-bittorrent", "torrent");
+        add("application/x-cdf", "cdf");
+        add("application/x-cdlink", "vcd");
+        add("application/x-chess-pgn", "pgn");
+        add("application/x-cpio", "cpio");
+        add("application/x-debian-package", "deb");
+        add("application/x-debian-package", "udeb");
+        add("application/x-director", "dcr");
+        add("application/x-director", "dir");
+        add("application/x-director", "dxr");
+        add("application/x-dms", "dms");
+        add("application/x-doom", "wad");
+        add("application/x-dvi", "dvi");
+        add("application/x-font", "pfa");
+        add("application/x-font", "pfb");
+        add("application/x-font", "gsf");
+        add("application/x-font", "pcf");
+        add("application/x-font", "pcf.Z");
+        add("application/x-freemind", "mm");
+        // application/futuresplash isn't IANA, so application/x-futuresplash should come first.
+        add("application/x-futuresplash", "spl");
+        add("application/futuresplash", "spl");
+        add("application/x-gnumeric", "gnumeric");
+        add("application/x-go-sgf", "sgf");
+        add("application/x-graphing-calculator", "gcf");
+        add("application/x-gtar", "tgz");
+        add("application/x-gtar", "gtar");
+        add("application/x-gtar", "taz");
+        add("application/x-hdf", "hdf");
+        add("application/x-ica", "ica");
+        add("application/x-internet-signup", "ins");
+        add("application/x-internet-signup", "isp");
+        add("application/x-iphone", "iii");
+        add("application/x-iso9660-image", "iso");
+        add("application/x-jmol", "jmz");
+        add("application/x-kchart", "chrt");
+        add("application/x-killustrator", "kil");
+        add("application/x-koan", "skp");
+        add("application/x-koan", "skd");
+        add("application/x-koan", "skt");
+        add("application/x-koan", "skm");
+        add("application/x-kpresenter", "kpr");
+        add("application/x-kpresenter", "kpt");
+        add("application/x-kspread", "ksp");
+        add("application/x-kword", "kwd");
+        add("application/x-kword", "kwt");
+        add("application/x-latex", "latex");
+        add("application/x-lha", "lha");
+        add("application/x-lzh", "lzh");
+        add("application/x-lzx", "lzx");
+        add("application/x-maker", "frm");
+        add("application/x-maker", "maker");
+        add("application/x-maker", "frame");
+        add("application/x-maker", "fb");
+        add("application/x-maker", "book");
+        add("application/x-maker", "fbdoc");
+        add("application/x-mif", "mif");
+        add("application/x-ms-wmd", "wmd");
+        add("application/x-ms-wmz", "wmz");
+        add("application/x-msi", "msi");
+        add("application/x-ns-proxy-autoconfig", "pac");
+        add("application/x-nwc", "nwc");
+        add("application/x-object", "o");
+        add("application/x-oz-application", "oza");
+        add("application/x-pem-file", "pem");
+        add("application/x-pkcs12", "p12");
+        add("application/x-pkcs12", "pfx");
+        add("application/x-pkcs7-certreqresp", "p7r");
+        add("application/x-pkcs7-crl", "crl");
+        add("application/x-quicktimeplayer", "qtl");
+        add("application/x-shar", "shar");
+        add("application/x-shockwave-flash", "swf");
+        add("application/x-stuffit", "sit");
+        add("application/x-sv4cpio", "sv4cpio");
+        add("application/x-sv4crc", "sv4crc");
+        add("application/x-tar", "tar");
+        add("application/x-texinfo", "texinfo");
+        add("application/x-texinfo", "texi");
+        add("application/x-troff", "t");
+        add("application/x-troff", "roff");
+        add("application/x-troff-man", "man");
+        add("application/x-ustar", "ustar");
+        add("application/x-wais-source", "src");
+        add("application/x-wingz", "wz");
+        add("application/x-webarchive", "webarchive");
+        add("application/x-webarchive-xml", "webarchivexml");
+        add("application/x-x509-ca-cert", "crt");
+        add("application/x-x509-user-cert", "crt");
+        add("application/x-x509-server-cert", "crt");
+        add("application/x-xcf", "xcf");
+        add("application/x-xfig", "fig");
+        add("application/xhtml+xml", "xhtml");
+        add("audio/3gpp", "3gpp");
+        add("audio/aac", "aac");
+        add("audio/aac-adts", "aac");
+        add("audio/amr", "amr");
+        add("audio/amr-wb", "awb");
+        add("audio/basic", "snd");
+        add("audio/flac", "flac");
+        add("application/x-flac", "flac");
+        add("audio/imelody", "imy");
+        add("audio/midi", "mid");
+        add("audio/midi", "midi");
+        add("audio/midi", "ota");
+        add("audio/midi", "kar");
+        add("audio/midi", "rtttl");
+        add("audio/midi", "xmf");
+        add("audio/mobile-xmf", "mxmf");
+        // add ".mp3" first so it will be the default for guessExtensionFromMimeType
+        add("audio/mpeg", "mp3");
+        add("audio/mpeg", "mpga");
+        add("audio/mpeg", "mpega");
+        add("audio/mpeg", "mp2");
+        add("audio/mpeg", "m4a");
+        add("audio/mpegurl", "m3u");
+        add("audio/prs.sid", "sid");
+        add("audio/x-aiff", "aif");
+        add("audio/x-aiff", "aiff");
+        add("audio/x-aiff", "aifc");
+        add("audio/x-gsm", "gsm");
+        add("audio/x-matroska", "mka");
+        add("audio/x-mpegurl", "m3u");
+        add("audio/x-ms-wma", "wma");
+        add("audio/x-ms-wax", "wax");
+        add("audio/x-pn-realaudio", "ra");
+        add("audio/x-pn-realaudio", "rm");
+        add("audio/x-pn-realaudio", "ram");
+        add("audio/x-realaudio", "ra");
+        add("audio/x-scpls", "pls");
+        add("audio/x-sd2", "sd2");
+        add("audio/x-wav", "wav");
+        // image/bmp isn't IANA, so image/x-ms-bmp should come first.
+        add("image/x-ms-bmp", "bmp");
+        add("image/bmp", "bmp");
+        add("image/gif", "gif");
+        // image/ico isn't IANA, so image/x-icon should come first.
+        add("image/x-icon", "ico");
+        add("image/ico", "cur");
+        add("image/ico", "ico");
+        add("image/ief", "ief");
+        // add ".jpg" first so it will be the default for guessExtensionFromMimeType
+        add("image/jpeg", "jpg");
+        add("image/jpeg", "jpeg");
+        add("image/jpeg", "jpe");
+        add("image/pcx", "pcx");
+        add("image/png", "png");
+        add("image/svg+xml", "svg");
+        add("image/svg+xml", "svgz");
+        add("image/tiff", "tiff");
+        add("image/tiff", "tif");
+        add("image/vnd.djvu", "djvu");
+        add("image/vnd.djvu", "djv");
+        add("image/vnd.wap.wbmp", "wbmp");
+        add("image/webp", "webp");
+        add("image/x-cmu-raster", "ras");
+        add("image/x-coreldraw", "cdr");
+        add("image/x-coreldrawpattern", "pat");
+        add("image/x-coreldrawtemplate", "cdt");
+        add("image/x-corelphotopaint", "cpt");
+        add("image/x-jg", "art");
+        add("image/x-jng", "jng");
+        add("image/x-photoshop", "psd");
+        add("image/x-portable-anymap", "pnm");
+        add("image/x-portable-bitmap", "pbm");
+        add("image/x-portable-graymap", "pgm");
+        add("image/x-portable-pixmap", "ppm");
+        add("image/x-rgb", "rgb");
+        add("image/x-xbitmap", "xbm");
+        add("image/x-xpixmap", "xpm");
+        add("image/x-xwindowdump", "xwd");
+        add("model/iges", "igs");
+        add("model/iges", "iges");
+        add("model/mesh", "msh");
+        add("model/mesh", "mesh");
+        add("model/mesh", "silo");
+        add("text/calendar", "ics");
+        add("text/calendar", "icz");
+        add("text/comma-separated-values", "csv");
+        add("text/css", "css");
+        add("text/html", "htm");
+        add("text/html", "html");
+        add("text/h323", "323");
+        add("text/iuls", "uls");
+        add("text/mathml", "mml");
+        // add ".txt" first so it will be the default for guessExtensionFromMimeType
+        add("text/plain", "txt");
+        add("text/plain", "asc");
+        add("text/plain", "text");
+        add("text/plain", "diff");
+        add("text/plain", "po");     // reserve "pot" for vnd.ms-powerpoint
+        add("text/richtext", "rtx");
+        add("text/rtf", "rtf");
+        add("text/text", "phps");
+        add("text/tab-separated-values", "tsv");
+        add("text/xml", "xml");
+        add("text/x-bibtex", "bib");
+        add("text/x-boo", "boo");
+        add("text/x-c++hdr", "hpp");
+        add("text/x-c++hdr", "h++");
+        add("text/x-c++hdr", "hxx");
+        add("text/x-c++hdr", "hh");
+        add("text/x-c++src", "cpp");
+        add("text/x-c++src", "c++");
+        add("text/x-c++src", "cc");
+        add("text/x-c++src", "cxx");
+        add("text/x-chdr", "h");
+        add("text/x-component", "htc");
+        add("text/x-csh", "csh");
+        add("text/x-csrc", "c");
+        add("text/x-dsrc", "d");
+        add("text/x-haskell", "hs");
+        add("text/x-java", "java");
+        add("text/x-literate-haskell", "lhs");
+        add("text/x-moc", "moc");
+        add("text/x-pascal", "p");
+        add("text/x-pascal", "pas");
+        add("text/x-pcs-gcd", "gcd");
+        add("text/x-setext", "etx");
+        add("text/x-tcl", "tcl");
+        add("text/x-tex", "tex");
+        add("text/x-tex", "ltx");
+        add("text/x-tex", "sty");
+        add("text/x-tex", "cls");
+        add("text/x-vcalendar", "vcs");
+        add("text/x-vcard", "vcf");
+        add("video/3gpp", "3gpp");
+        add("video/3gpp", "3gp");
+        add("video/3gpp2", "3gpp2");
+        add("video/3gpp2", "3g2");
+        add("video/avi", "avi");
+        add("video/dl", "dl");
+        add("video/dv", "dif");
+        add("video/dv", "dv");
+        add("video/fli", "fli");
+        add("video/m4v", "m4v");
+        add("video/mp2ts", "ts");
+        add("video/mpeg", "mpeg");
+        add("video/mpeg", "mpg");
+        add("video/mpeg", "mpe");
+        add("video/mp4", "mp4");
+        add("video/mpeg", "VOB");
+        add("video/quicktime", "qt");
+        add("video/quicktime", "mov");
+        add("video/vnd.mpegurl", "mxu");
+        add("video/webm", "webm");
+        add("video/x-la-asf", "lsf");
+        add("video/x-la-asf", "lsx");
+        add("video/x-matroska", "mkv");
+        add("video/x-mng", "mng");
+        add("video/x-ms-asf", "asf");
+        add("video/x-ms-asf", "asx");
+        add("video/x-ms-wm", "wm");
+        add("video/x-ms-wmv", "wmv");
+        add("video/x-ms-wmx", "wmx");
+        add("video/x-ms-wvx", "wvx");
+        add("video/x-sgi-movie", "movie");
+        add("video/x-webex", "wrf");
+        add("x-conference/x-cooltalk", "ice");
+        add("x-epoc/x-sisx-app", "sisx");
+        applyOverrides();
+    }
+    private static void add(String mimeType, String extension) {
+        // If we have an existing x -> y mapping, we do not want to
+        // override it with another mapping x -> y2.
+        // If a mime type maps to several extensions
+        // the first extension added is considered the most popular
+        // so we do not want to overwrite it later.
+        if (!mimeTypeToExtensionMap.containsKey(mimeType)) {
+            mimeTypeToExtensionMap.put(mimeType, extension);
+        }
+        if (!extensionToMimeTypeMap.containsKey(extension)) {
+            extensionToMimeTypeMap.put(extension, mimeType);
+        }
+    }
+    private static InputStream getContentTypesPropertiesStream() {
+        // User override?
+        String userTable = System.getProperty("content.types.user.table");
+        if (userTable != null) {
+            File f = new File(userTable);
+            if (f.exists()) {
+                try {
+                    return new FileInputStream(f);
+                } catch (IOException ignored) {
+                }
+            }
+        }
+        // Standard location?
+        File f = new File(System.getProperty("java.home"), "lib" + File.separator + "content-types.properties");
+        if (f.exists()) {
+            try {
+                return new FileInputStream(f);
+            } catch (IOException ignored) {
+            }
+        }
+        return null;
+    }
+    /**
+     * This isn't what the RI does. The RI doesn't have hard-coded defaults, so supplying your
+     * own "content.types.user.table" means you don't get any of the built-ins, and the built-ins
+     * come from "$JAVA_HOME/lib/content-types.properties".
+     */
+    private static void applyOverrides() {
+        // Get the appropriate InputStream to read overrides from, if any.
+        InputStream stream = getContentTypesPropertiesStream();
+        if (stream == null) {
+            return;
+        }
+        try {
+            try {
+                // Read the properties file...
+                Properties overrides = new Properties();
+                overrides.load(stream);
+                // And translate its mapping to ours...
+                for (Map.Entry<Object, Object> entry : overrides.entrySet()) {
+                    String extension = (String) entry.getKey();
+                    String mimeType = (String) entry.getValue();
+                    add(mimeType, extension);
+                }
+            } finally {
+                stream.close();
+            }
+        } catch (IOException ignored) {
+        }
+    }
+    private MimeUtils() {
+    }
+    /**
+     * Returns true if the given MIME type has an entry in the map.
+     * @param mimeType A MIME type (i.e. text/plain)
+     * @return True iff there is a mimeType entry in the map.
+     */
+    public static boolean hasMimeType(String mimeType) {
+        if (mimeType == null || mimeType.isEmpty()) {
+            return false;
+        }
+        return mimeTypeToExtensionMap.containsKey(mimeType);
+    }
+    /**
+     * Returns the MIME type for the given extension.
+     * @param extension A file extension without the leading '.'
+     * @return The MIME type for the given extension or null iff there is none.
+     */
+    public static String guessMimeTypeFromExtension(String extension) {
+        if (extension == null || extension.isEmpty()) {
+            return null;
+        }
+        return extensionToMimeTypeMap.get(extension);
+    }
+    /**
+     * Returns true if the given extension has a registered MIME type.
+     * @param extension A file extension without the leading '.'
+     * @return True iff there is an extension entry in the map.
+     */
+    public static boolean hasExtension(String extension) {
+        if (extension == null || extension.isEmpty()) {
+            return false;
+        }
+        return extensionToMimeTypeMap.containsKey(extension);
+    }
+    /**
+     * Returns the registered extension for the given MIME type. Note that some
+     * MIME types map to multiple extensions. This call will return the most
+     * common extension for the given MIME type.
+     * @param mimeType A MIME type (i.e. text/plain)
+     * @return The extension for the given MIME type or null iff there is none.
+     */
+    public static String guessExtensionFromMimeType(String mimeType) {
+        if (mimeType == null || mimeType.isEmpty()) {
+            return null;
+        }
+        return mimeTypeToExtensionMap.get(mimeType);
+    }
+}
diff --git a/src/main/java/eu/siacs/conversations/utils/UIHelper.java b/src/main/java/eu/siacs/conversations/utils/UIHelper.java
index 2f96a83a9..19a8653f6 100644
--- a/src/main/java/eu/siacs/conversations/utils/UIHelper.java
+++ b/src/main/java/eu/siacs/conversations/utils/UIHelper.java
@@ -199,16 +199,7 @@ public class UIHelper {
 		if (message.getType() == Message.TYPE_IMAGE) {
 			return context.getString(R.string.image);
 		}
-		final String path = message.getRelativeFilePath();
-		if (path == null) {
-			return "";
-		}
-		final String mime;
-		try {
-			mime = URLConnection.guessContentTypeFromName(path.replace("#",""));
-		} catch (final StringIndexOutOfBoundsException ignored) {
-			return context.getString(R.string.file);
-		}
+		final String mime = message.getMimeType();
 		if (mime == null) {
 			return context.getString(R.string.file);
 		} else if (mime.startsWith("audio/")) {