Bug 990642 - Try harder to find an extension to use when sharing images. r=mfinkle

mobile/android/base/GeckoAppShell.java

@@ -109,6 +109,7 @@ import android.view.TextureView;
 import android.view.View;
 import android.view.inputmethod.InputMethodManager;
 import android.webkit.MimeTypeMap;
+import android.webkit.URLUtil;
 import android.widget.AbsoluteLayout;
 import android.widget.Toast;
 
@@ -2657,37 +2658,53 @@ public class GeckoAppShell
 
         GeckoApp.deleteTempFiles();
 
+        String type = intent.getType();
         OutputStream os = null;
         try {
             // Create a temporary file for the image
-            final String type = intent.getType().replace("image/", "");
-            final File imageFile = File.createTempFile("image", "." + type, dir);
-            os = new FileOutputStream(imageFile);
-
             if (src.startsWith("data:")) {
-                int dataStart = src.indexOf(",");
+                final int dataStart = src.indexOf(",");
+
+                String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(type);
+
+                // If we weren't given an explicit mimetype, try to dig one out of the data uri.
+                if (TextUtils.isEmpty(extension) && dataStart > 5) {
+                    type = src.substring(5, dataStart).replace(";base64", "");
+                    extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(type);
+                }
+
+                final File imageFile = File.createTempFile("image", "." + extension, dir);
+                os = new FileOutputStream(imageFile);
+
                 byte[] buf = Base64.decode(src.substring(dataStart + 1), Base64.DEFAULT);
                 os.write(buf);
 
+                // Only alter the intent when we're sure everything has worked
                 intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(imageFile));
             } else {
                 InputStream is = null;
                 try {
                     final byte[] buf = new byte[2048];
                     final URL url = new URL(src);
+                    final String filename = URLUtil.guessFileName(src, null, type);
                     is = url.openStream();
 
+                    final File imageFile = new File(dir, filename);
+                    os = new FileOutputStream(imageFile);
+
                     int length;
                     while ((length = is.read(buf)) != -1) {
                         os.write(buf, 0, length);
                     }
 
+                    // Only alter the intent when we're sure everything has worked
                     intent.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(imageFile));
                 } finally {
                     safeStreamClose(is);
                 }
             }
         } catch(IOException ex) {
+            // If something went wrong, we'll just leave the intent un-changed
         } finally {
             safeStreamClose(os);
         }

mobile/android/base/widget/GeckoActionProvider.java

@@ -5,6 +5,7 @@
 
 package org.mozilla.gecko.widget;
 
+import org.mozilla.gecko.GeckoAppShell;
 import org.mozilla.gecko.Telemetry;
 import org.mozilla.gecko.TelemetryContract;
 import org.mozilla.gecko.menu.MenuItemActionView;