Make sure SearchDialog.mSearchable != null in key handlers

This change adds checking that the searchdialog is initialized
properly to a few key event listeners where it was missing
before.

Also makes sure that the search dialog is not shown if the
global search is requested but the global search provider
cannot be found.

Should fix http://b/issue?id=1982128
"Device rebooting after search results"
where SearchDialog.onKeyDown() threw an NPE
diff --git a/core/java/android/app/SearchDialog.java b/core/java/android/app/SearchDialog.java
index e70b570..bfd9923 100644
--- a/core/java/android/app/SearchDialog.java
+++ b/core/java/android/app/SearchDialog.java
@@ -28,7 +28,6 @@
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.content.pm.PackageManager.NameNotFoundException;
-import android.content.res.Configuration;
 import android.content.res.Resources;
 import android.database.Cursor;
 import android.graphics.drawable.Animatable;
@@ -322,16 +321,14 @@
         if (!globalSearch && mSearchable == null) {
             globalSearch = true;
             mSearchable = searchManager.getSearchableInfo(componentName, globalSearch);
-            
-            // If we still get back null (i.e., there's not even a searchable info available
-            // for global search), then really give up.
-            if (mSearchable == null) {
-                // Unfortunately, we can't log here.  it would be logspam every time the user
-                // clicks the "search" key on a non-search app.
-                return false;
-            }
         }
-        
+
+        // If there's not even a searchable info available for global search, then really give up.
+        if (mSearchable == null) {
+            Log.w(LOG_TAG, "No global search provider.");
+            return false;
+        }
+
         mLaunchComponent = componentName;
         mAppSearchData = appSearchData;
         // Using globalSearch here is just an optimization, just calling
@@ -702,7 +699,10 @@
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
         if (DBG) Log.d(LOG_TAG, "onKeyDown(" + keyCode + "," + event + ")");
-        
+        if (mSearchable == null) {
+            return false;
+        }
+
         // handle back key to go back to previous searchable, etc.
         if (handleBackKey(keyCode, event)) {
             return true;
@@ -738,6 +738,9 @@
             if (DBG_LOG_TIMING) {
                 dbgLogTiming("onTextChanged()");
             }
+            if (mSearchable == null) {
+                return;
+            }
             updateWidgetState();
             if (!mSearchAutoComplete.isPerformingCompletion()) {
                 // The user changed the query, remember it.
@@ -1563,6 +1566,9 @@
          */
         @Override
         public boolean onKeyPreIme(int keyCode, KeyEvent event) {
+            if (mSearchDialog.mSearchable == null) {
+                return false;
+            }
             if (keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN) {
                 if (mSearchDialog.backToPreviousComponent()) {
                     return true;