Enable opening mailto URLs under Android

* doc/emacs/android.texi (Android Startup): Mention how mailto
URLs are treated by the emacsclient wrapper.

* java/AndroidManifest.xml.in: Register `mailto' scheme filters
for EmacsOpenActivity.

* java/org/gnu/emacs/EmacsOpenActivity.java (startEmacsClient):
Extract code that starts Emacs when it isn't already running,
and take a list of arguments rather than a single file name.
(onCreate): If the scheme is `mailto', escape the URI and call
`message-mailto'.

1 files changed, 7 insertions, 0 deletions

diff --git a/doc/emacs/android.texi b/doc/emacs/android.texi
index b8862b244d2..07b689ca23b 100644
--- a/doc/emacs/android.texi
+++ b/doc/emacs/android.texi
@@ -158,6 +158,13 @@ opened.
 @command{emacsclient} wrapper as a program capable of opening
 ``org-protocol'' links (@pxref{Protocols,,,org, The Org Manual}).
 
+@cindex ``mailto'' links, android
+  Furthermore, the wrapper is also registered as a program capable of
+sending mail to @code{mailto} URIs; when it is invoked to open such a
+URL, it calls the function @code{message-mailto} with that URI as its
+first argument.  This feature does not function when the Emacs server
+is not already running.
+
 @node Android File System
 @section What Files Emacs Can Access on Android
 @cindex /assets directory, android