diff --git a/core/java/android/webkit/LoadListener.java b/core/java/android/webkit/LoadListener.java
index 7cbbce2e2de12..c0b6dab54c29f 100644
--- a/core/java/android/webkit/LoadListener.java
+++ b/core/java/android/webkit/LoadListener.java
@@ -38,6 +38,7 @@ import com.android.internal.R;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Vector;
 import java.util.regex.Pattern;
@@ -70,7 +71,12 @@ class LoadListener extends Handler implements EventHandler {
     private static final int HTTP_NOT_FOUND = 404;
     private static final int HTTP_PROXY_AUTH = 407;
 
-    private static final String CERT_MIMETYPE = "application/x-x509-ca-cert";
+    private static HashSet<String> sCertificateMimeTypeMap;
+    static {
+        sCertificateMimeTypeMap = new HashSet<String>();
+        sCertificateMimeTypeMap.add("application/x-x509-ca-cert");
+        sCertificateMimeTypeMap.add("application/x-pkcs12");
+    }
 
     private static int sNativeLoaderCount;
 
@@ -311,7 +317,17 @@ class LoadListener extends Handler implements EventHandler {
             if (mMimeType.equals("text/plain") ||
                     mMimeType.equals("application/octet-stream")) {
 
-                String newMimeType = guessMimeTypeFromExtension();
+                // for attachment, use the filename in the Content-Disposition
+                // to guess the mimetype
+                String contentDisposition = headers.getContentDisposition();
+                String url = null;
+                if (contentDisposition != null) {
+                    url = URLUtil.parseContentDisposition(contentDisposition);
+                }
+                if (url == null) {
+                    url = mUrl;
+                }
+                String newMimeType = guessMimeTypeFromExtension(url);
                 if (newMimeType != null) {
                     mMimeType = newMimeType;
                 }
@@ -918,7 +934,7 @@ class LoadListener extends Handler implements EventHandler {
 
     // This commits the headers without checking the response status code.
     private void commitHeaders() {
-        if (mIsMainPageLoader && CERT_MIMETYPE.equals(mMimeType)) {
+        if (mIsMainPageLoader && sCertificateMimeTypeMap.contains(mMimeType)) {
             // In the case of downloading certificate, we will save it to the
             // Keystore in commitLoad. Do not call webcore.
             return;
@@ -963,7 +979,7 @@ class LoadListener extends Handler implements EventHandler {
     private void commitLoad() {
         if (mCancelled) return;
 
-        if (mIsMainPageLoader && CERT_MIMETYPE.equals(mMimeType)) {
+        if (mIsMainPageLoader && sCertificateMimeTypeMap.contains(mMimeType)) {
             // In the case of downloading certificate, we will save it to the
             // Keystore and stop the current loading so that it will not
             // generate a new history page
@@ -1393,7 +1409,7 @@ class LoadListener extends Handler implements EventHandler {
             // of frames. If no content-type was specified, it is fine to
             // default to text/html.
             mMimeType = "text/html";
-            String newMimeType = guessMimeTypeFromExtension();
+            String newMimeType = guessMimeTypeFromExtension(mUrl);
             if (newMimeType != null) {
                 mMimeType = newMimeType;
             }
@@ -1403,14 +1419,14 @@ class LoadListener extends Handler implements EventHandler {
     /**
      * guess MIME type based on the file extension.
      */
-    private String guessMimeTypeFromExtension() {
+    private String guessMimeTypeFromExtension(String url) {
         // PENDING: need to normalize url
         if (DebugFlags.LOAD_LISTENER) {
-            Log.v(LOGTAG, "guessMimeTypeFromExtension: mURL = " + mUrl);
+            Log.v(LOGTAG, "guessMimeTypeFromExtension: url = " + url);
         }
 
         return MimeTypeMap.getSingleton().getMimeTypeFromExtension(
-                MimeTypeMap.getFileExtensionFromUrl(mUrl));
+                MimeTypeMap.getFileExtensionFromUrl(url));
     }
 
     /**
diff --git a/core/java/android/webkit/MimeTypeMap.java b/core/java/android/webkit/MimeTypeMap.java
index 096f38add65b6..648ec27aea5c9 100644
--- a/core/java/android/webkit/MimeTypeMap.java
+++ b/core/java/android/webkit/MimeTypeMap.java
@@ -335,6 +335,7 @@ public /* package */ class MimeTypeMap {
             sMimeTypeMap.loadEntry("application/x-object", "o", false);
             sMimeTypeMap.loadEntry("application/x-oz-application", "oza", 
                     false);
+            sMimeTypeMap.loadEntry("application/x-pkcs12", "p12", false);
             sMimeTypeMap.loadEntry("application/x-pkcs7-certreqresp", "p7r", 
                     false);
             sMimeTypeMap.loadEntry("application/x-pkcs7-crl", "crl", false);
diff --git a/core/java/android/webkit/URLUtil.java b/core/java/android/webkit/URLUtil.java
index de70fc2d2b652..1d18289993052 100644
--- a/core/java/android/webkit/URLUtil.java
+++ b/core/java/android/webkit/URLUtil.java
@@ -348,7 +348,7 @@ public final class URLUtil {
      * This header provides a filename for content that is going to be
      * downloaded to the file system. We only support the attachment type.
      */
-    private static String parseContentDisposition(String contentDisposition) {
+    static String parseContentDisposition(String contentDisposition) {
         try {
             Matcher m = CONTENT_DISPOSITION_PATTERN.matcher(contentDisposition);
             if (m.find()) {