Update Android port

* doc/emacs/android.texi (Android Startup): Document `content'
special directory.
* java/debug.sh (is_root): Improve /bin/tee detection.
* java/org/gnu/emacs/EmacsNative.java (EmacsNative): New
function `dup'.
* java/org/gnu/emacs/EmacsOpenActivity.java (EmacsOpenActivity)
(checkReadableOrCopy, onCreate): Create content directory names
when the file is not readable.
* java/org/gnu/emacs/EmacsService.java (EmacsService)
(openContentUri, checkContentUri): New functions.
* src/android.c (struct android_emacs_service): New methods.
(android_content_name_p, android_get_content_name)
(android_check_content_access): New function.
(android_fstatat, android_open): Implement opening content URIs.
(dup): Export to Java.
(android_init_emacs_service): Initialize new methods.
(android_faccessat): Implement content file names.

java/org/gnu/emacs/EmacsNative.java

@@ -31,6 +31,10 @@ public class EmacsNative
      initialization.  */
   private static final String[] libraryDeps;
 
+
+  /* Like `dup' in C.  */
+  public static native int dup (int fd);
+
   /* Obtain the fingerprint of this build of Emacs.  The fingerprint
      can be used to determine the dump file name.  */
   public static native String getFingerprint ();

java/org/gnu/emacs/EmacsOpenActivity.java

@@ -57,6 +57,8 @@ import android.os.Build;
 import android.os.Bundle;
 import android.os.ParcelFileDescriptor;
 
+import android.util.Log;
+
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
@@ -69,6 +71,8 @@ import java.io.UnsupportedEncodingException;
 public class EmacsOpenActivity extends Activity
   implements DialogInterface.OnClickListener
 {
+  private static final String TAG = "EmacsOpenActivity";
+
   private class EmacsClientThread extends Thread
   {
     private ProcessBuilder builder;
@@ -178,12 +182,16 @@ public class EmacsOpenActivity extends Activity
     dialog.show ();
   }
 
-  /* Check that the specified FILE is readable.  If it is not, then
-     copy the file in FD to a location in the system cache
-     directory and return the name of that file.  */
+  /* Check that the specified FILE is readable.  If Android 4.4 or
+     later is being used, return URI formatted into a `/content/' file
+     name.
+
+     If it is not, then copy the file in FD to a location in the
+     system cache directory and return the name of that file.  */
 
   private String
-  checkReadableOrCopy (String file, ParcelFileDescriptor fd)
+  checkReadableOrCopy (String file, ParcelFileDescriptor fd,
+		       Uri uri)
     throws IOException, FileNotFoundException
   {
     File inFile;
@@ -191,12 +199,34 @@ public class EmacsOpenActivity extends Activity
     InputStream stream;
     byte buffer[];
     int read;
+    String content;
+
+    Log.d (TAG, "checkReadableOrCopy: " + file);
 
     inFile = new File (file);
 
-    if (inFile.setReadable (true))
+    if (inFile.canRead ())
       return file;
 
+    Log.d (TAG, "checkReadableOrCopy: NO");
+
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT)
+      {
+	content = "/content/" + uri.getEncodedAuthority ();
+
+	for (String segment : uri.getPathSegments ())
+	  content += "/" + Uri.encode (segment);
+
+	/* Append the URI query.  */
+
+	if (uri.getEncodedQuery () != null)
+	  content += "?" + uri.getEncodedQuery ();
+
+	Log.d (TAG, "checkReadableOrCopy: " + content);
+
+	return content;
+      }
+
     /* inFile is now the file being written to.  */
     inFile = new File (getCacheDir (), inFile.getName ());
     buffer = new byte[4098];
@@ -398,7 +428,7 @@ public class EmacsOpenActivity extends Activity
 		    if (names != null)
 		      fileName = new String (names, "UTF-8");
 
-		    fileName = checkReadableOrCopy (fileName, fd);
+		    fileName = checkReadableOrCopy (fileName, fd, uri);
 		  }
 		catch (FileNotFoundException exception)
 		  {

java/org/gnu/emacs/EmacsService.java

@@ -19,7 +19,10 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 
 package org.gnu.emacs;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+
 import java.util.List;
 import java.util.ArrayList;
 
@@ -41,22 +44,31 @@ import android.app.Service;
 
 import android.content.ClipboardManager;
 import android.content.Context;
+import android.content.ContentResolver;
 import android.content.Intent;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager.ApplicationInfoFlags;
 import android.content.pm.PackageManager;
 import android.content.res.AssetManager;
 
+import android.database.Cursor;
+import android.database.MatrixCursor;
+
+
 import android.net.Uri;
 
 import android.os.Build;
 import android.os.Looper;
 import android.os.IBinder;
 import android.os.Handler;
+import android.os.ParcelFileDescriptor;
 import android.os.Vibrator;
 import android.os.VibratorManager;
 import android.os.VibrationEffect;
 
+import android.provider.DocumentsContract;
+import android.provider.DocumentsContract.Document;
+
 import android.util.Log;
 import android.util.DisplayMetrics;
 
@@ -79,6 +91,7 @@ public class EmacsService extends Service
 
   private EmacsThread thread;
   private Handler handler;
+  private ContentResolver resolver;
 
   /* Keep this in synch with androidgui.h.  */
   public static final int IC_MODE_NULL   = 0;
@@ -193,6 +206,7 @@ public class EmacsService extends Service
     metrics = getResources ().getDisplayMetrics ();
     pixelDensityX = metrics.xdpi;
     pixelDensityY = metrics.ydpi;
+    resolver = getContentResolver ();
 
     try
       {
@@ -643,4 +657,109 @@ public class EmacsService extends Service
     window.view.setICMode (icMode);
     window.view.imManager.restartInput (window.view);
   }
+
+  /* Open a content URI described by the bytes BYTES, a non-terminated
+     string; make it writable if WRITABLE, and readable if READABLE.
+     Truncate the file if TRUNCATE.
+
+     Value is the resulting file descriptor or -1 upon failure.  */
+
+  public int
+  openContentUri (byte[] bytes, boolean writable, boolean readable,
+		  boolean truncate)
+  {
+    String name, mode;
+    ParcelFileDescriptor fd;
+    int i;
+
+    /* Figure out the file access mode.  */
+
+    mode = "";
+
+    if (readable)
+      mode += "r";
+
+    if (writable)
+      mode += "w";
+
+    if (truncate)
+      mode += "t";
+
+    /* Try to open an associated ParcelFileDescriptor.  */
+
+    try
+      {
+	/* The usual file name encoding question rears its ugly head
+	   again.  */
+	name = new String (bytes, "UTF-8");
+	Log.d (TAG, "openContentUri: " + Uri.parse (name));
+
+	fd = resolver.openFileDescriptor (Uri.parse (name), mode);
+
+	/* Use detachFd on newer versions of Android or plain old
+	   dup.  */
+
+	if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB_MR1)
+	  {
+	    i = fd.detachFd ();
+	    fd.close ();
+
+	    return i;
+	  }
+	else
+	  {
+	    i = EmacsNative.dup (fd.getFd ());
+	    fd.close ();
+
+	    return i;
+	  }
+      }
+    catch (Exception exception)
+      {
+	return -1;
+      }
+  }
+
+  public boolean
+  checkContentUri (byte[] string, boolean readable, boolean writable)
+  {
+    String mode, name;
+    ParcelFileDescriptor fd;
+
+    /* Decode this into a URI.  */
+
+    try
+      {
+	/* The usual file name encoding question rears its ugly head
+	   again.  */
+	name = new String (string, "UTF-8");
+	Log.d (TAG, "checkContentUri: " + Uri.parse (name));
+      }
+    catch (UnsupportedEncodingException exception)
+      {
+	name = null;
+	throw new RuntimeException (exception);
+      }
+
+    mode = "r";
+
+    if (writable)
+      mode += "w";
+
+    try
+      {
+	fd = resolver.openFileDescriptor (Uri.parse (name), mode);
+	fd.close ();
+
+	Log.d (TAG, "checkContentUri: YES");
+
+	return true;
+      }
+    catch (Exception exception)
+      {
+	Log.d (TAG, "checkContentUri: NO");
+	Log.d (TAG, exception.toString ());
+	return false;
+      }
+  }
 };