Update Android port

* java/org/gnu/emacs/EmacsNoninteractive.java (main): Port to
Android 2.2.
* src/android-asset.h (AAsset_openFileDescriptor): Delete stub
function.
* src/android.c (android_check_compressed_file): Delete
function.
(android_open): Stop trying to find compressed files or to use
the system provided file descriptor.  Explain why.

3 files changed, 87 insertions, 105 deletions

diff --git a/java/org/gnu/emacs/EmacsNoninteractive.java b/java/org/gnu/emacs/EmacsNoninteractive.java
index 4da82f2f894..30901edb75f 100644
--- a/java/org/gnu/emacs/EmacsNoninteractive.java
+++ b/java/org/gnu/emacs/EmacsNoninteractive.java
@@ -87,56 +87,23 @@ public class EmacsNoninteractive
 
         /* Create and attach the activity thread.  */
         activityThread = method.invoke (null);
+        context = null;
 
         /* Now get an LoadedApk.  */
-        loadedApkClass = Class.forName ("android.app.LoadedApk");
 
-        /* Get a LoadedApk.  How to do this varies by Android version.
-           On Android 2.3.3 and earlier, there is no
-           ``compatibilityInfo'' argument to getPackageInfo.  */
-
-        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.GINGERBREAD_MR1)
+        try
           {
-            method
-              = activityThreadClass.getMethod ("getPackageInfo",
-                                               String.class,
-                                               int.class);
-            loadedApk = method.invoke (activityThread, "org.gnu.emacs",
-                                       0);
+            loadedApkClass = Class.forName ("android.app.LoadedApk");
           }
-        else
+        catch (ClassNotFoundException exception)
           {
-            compatibilityInfoClass
-              = Class.forName ("android.content.res.CompatibilityInfo");
-
-            method
-              = activityThreadClass.getMethod ("getPackageInfo",
-                                               String.class,
-                                               compatibilityInfoClass,
-                                               int.class);
-            loadedApk = method.invoke (activityThread, "org.gnu.emacs", null,
-                                       0);
-          }
-
-        if (loadedApk == null)
-          throw new RuntimeException ("getPackageInfo returned NULL");
+            /* Android 2.2 has no LoadedApk class, but fortunately it
+               does not need to be used, since contexts can be
+               directly created.  */
 
-        /* Now, get a context.  */
-        contextImplClass = Class.forName ("android.app.ContextImpl");
+            loadedApkClass = null;
+            contextImplClass = Class.forName ("android.app.ContextImpl");
 
-        try
-          {
-            method = contextImplClass.getDeclaredMethod ("createAppContext",
-                                                         activityThreadClass,
-                                                         loadedApkClass);
-            method.setAccessible (true);
-            context = (Context) method.invoke (null, activityThread, loadedApk);
-          }
-        catch (NoSuchMethodException exception)
-          {
-            /* Older Android versions don't have createAppContext, but
-               instead require creating a ContextImpl, and then
-               calling createPackageContext.  */
             method = activityThreadClass.getDeclaredMethod ("getSystemContext");
             context = (Context) method.invoke (activityThread);
             method = contextImplClass.getDeclaredMethod ("createPackageContext",
@@ -147,6 +114,73 @@ public class EmacsNoninteractive
                                                0);
           }
 
+        /* If the context has not already been created, then do what
+           is appropriate for newer versions of Android.  */
+
+        if (context == null)
+          {
+            /* Get a LoadedApk.  How to do this varies by Android version.
+               On Android 2.3.3 and earlier, there is no
+               ``compatibilityInfo'' argument to getPackageInfo.  */
+
+            if (Build.VERSION.SDK_INT
+                <= Build.VERSION_CODES.GINGERBREAD_MR1)
+              {
+                method
+                  = activityThreadClass.getMethod ("getPackageInfo",
+                                                   String.class,
+                                                   int.class);
+                loadedApk = method.invoke (activityThread, "org.gnu.emacs",
+                                           0);
+              }
+            else
+              {
+                compatibilityInfoClass
+                  = Class.forName ("android.content.res.CompatibilityInfo");
+
+                method
+                  = activityThreadClass.getMethod ("getPackageInfo",
+                                                   String.class,
+                                                   compatibilityInfoClass,
+                                                   int.class);
+                loadedApk = method.invoke (activityThread, "org.gnu.emacs",
+                                           null, 0);
+              }
+
+            if (loadedApk == null)
+              throw new RuntimeException ("getPackageInfo returned NULL");
+
+            /* Now, get a context.  */
+            contextImplClass = Class.forName ("android.app.ContextImpl");
+
+            try
+              {
+                method
+                  = contextImplClass.getDeclaredMethod ("createAppContext",
+                                                        activityThreadClass,
+                                                        loadedApkClass);
+                method.setAccessible (true);
+                context = (Context) method.invoke (null, activityThread,
+                                                   loadedApk);
+              }
+            catch (NoSuchMethodException exception)
+              {
+                /* Older Android versions don't have createAppContext, but
+                   instead require creating a ContextImpl, and then
+                   calling createPackageContext.  */
+                method
+                  = activityThreadClass.getDeclaredMethod ("getSystemContext");
+                context = (Context) method.invoke (activityThread);
+                method
+                  = contextImplClass.getDeclaredMethod ("createPackageContext",
+                                                        String.class,
+                                                        int.class);
+                method.setAccessible (true);
+                context = (Context) method.invoke (context, "org.gnu.emacs",
+                                                   0);
+              }
+          }
+
         /* Don't actually start the looper or anything.  Instead, obtain
            an AssetManager.  */
         assets = context.getAssets ();
diff --git a/src/android-asset.h b/src/android-asset.h
index b0e83bbf424..3b2f8105865 100644
--- a/src/android-asset.h
+++ b/src/android-asset.h
@@ -365,15 +365,6 @@ android_asset_read_internal (AAsset *asset, int nbytes, char *buffer)
   return total;
 }
 
-static int
-AAsset_openFileDescriptor (AAsset *asset, off_t *out_start,
-                           off_t *out_end)
-{
-  *out_start = 0;
-  *out_end = 0;
-  return -1;
-}
-
 static long
 AAsset_getLength (AAsset *asset)
 {
diff --git a/src/android.c b/src/android.c
index 72c50c0a13c..40d6234d508 100644
--- a/src/android.c
+++ b/src/android.c
@@ -1376,42 +1376,6 @@ android_hack_asset_fd (AAsset *asset)
 #endif
 }
 
-/* Read two bytes from FD and see if they are ``PK'', denoting ZIP
-   archive compressed data.  If FD is -1, return -1.
-
-   If they are not, rewind the file descriptor to offset 0.
-
-   If either operation fails, return -1 and close FD.  Else, value is
-   FD.  */
-
-static int
-android_check_compressed_file (int fd)
-{
-  char bytes[2];
-
-  if (fd == -1)
-    return -1;
-
-  if (read (fd, bytes, 2) != 2)
-    goto lseek_back;
-
-  if (bytes[0] != 'P' || bytes[1] != 'K')
-    goto lseek_back;
-
-  /* This could be compressed data! */
-  return -1;
-
- lseek_back:
-  /* Seek back to offset 0.  If this fails, return -1.  */
-  if (lseek (fd, 0, SEEK_SET) != 0)
-    {
-      close (fd);
-      return -1;
-    }
-
-  return fd;
-}
-
 /* Make FD close-on-exec.  If any system call fails, do not abort, but
    log a warning to the system log.  */
 
@@ -1482,28 +1446,21 @@ android_open (const char *filename, int oflag, int mode)
           return -1;
         }
 
-      /* Try to obtain the file descriptor corresponding to this
-         asset.  */
-      fd = AAsset_openFileDescriptor (asset, &out_start,
-                                      &out_length);
+      /* Create a shared memory file descriptor containing the asset
+         contents.
+
+         The documentation misleads people into thinking that
+         AAsset_openFileDescriptor does precisely this.  However, it
+         instead returns an offset into any uncompressed assets in the
+         ZIP archive.  This cannot be found in its documentation.  */
 
-      /* The platform sometimes returns a file descriptor to ZIP
-         compressed data.  Detect that and fall back to creating a
-         shared memory file descriptor.  */
-      fd = android_check_compressed_file (fd);
+      fd = android_hack_asset_fd (asset);
 
       if (fd == -1)
         {
-          /* The asset can't be accessed for some reason.  Try to
-             create a shared memory file descriptor.  */
-          fd = android_hack_asset_fd (asset);
-
-          if (fd == -1)
-            {
-              AAsset_close (asset);
-              errno = ENXIO;
-              return -1;
-            }
+          AAsset_close (asset);
+          errno = ENXIO;
+          return -1;
         }
 
       /* If O_CLOEXEC is specified, make the file descriptor close on