Straighten out database cursors behavior.

Some were never closed, other closed twice. This change
makes all Cursor instances behave, having the #close()
call in a finally{} clause, and puts the burden of closing
the cursor squarely on the creator rather than in the
called methods.
There is however one exception that is beyond the scope
of this change: UserDictionarySettings have a Cursor
member, it's never closed, and fixing the problem is not
obvious. This change adds a TODO for now.

It's not very clear if this change actually helps with
bug#12670151, but it may be related and it's a good
think to do anyway.

Bug: 12670151
Change-Id: I87cc44387e7dee3da1488671b93a28d9d73f7dc0

1 files changed, 39 insertions, 19 deletions

diff --git a/java/src/com/android/inputmethod/dictionarypack/MetadataDbHelper.java b/java/src/com/android/inputmethod/dictionarypack/MetadataDbHelper.java
index ff5aba6d8..8badaf4b9 100644
--- a/java/src/com/android/inputmethod/dictionarypack/MetadataDbHelper.java
+++ b/java/src/com/android/inputmethod/dictionarypack/MetadataDbHelper.java
@@ -533,12 +533,17 @@ public class MetadataDbHelper extends SQLiteOpenHelper {
                 PENDINGID_COLUMN + "= ?",
                 new String[] { Long.toString(id) },
                 null, null, null);
-        // There should never be more than one result. If because of some bug there are, returning
-        // only one result is the right thing to do, because we couldn't handle several anyway
-        // and we should still handle one.
-        final ContentValues result = getFirstLineAsContentValues(cursor);
-        cursor.close();
-        return result;
+        if (null == cursor) {
+            return null;
+        }
+        try {
+            // There should never be more than one result. If because of some bug there are,
+            // returning only one result is the right thing to do, because we couldn't handle
+            // several anyway and we should still handle one.
+            return getFirstLineAsContentValues(cursor);
+        } finally {
+            cursor.close();
+        }
     }
 
     /**
@@ -559,11 +564,16 @@ public class MetadataDbHelper extends SQLiteOpenHelper {
                 new String[] { id, Integer.toString(STATUS_INSTALLED),
                         Integer.toString(STATUS_DELETING) },
                 null, null, null);
-        // There should only be one result, but if there are several, we can't tell which
-        // is the best, so we just return the first one.
-        final ContentValues result = getFirstLineAsContentValues(cursor);
-        cursor.close();
-        return result;
+        if (null == cursor) {
+            return null;
+        }
+        try {
+            // There should only be one result, but if there are several, we can't tell which
+            // is the best, so we just return the first one.
+            return getFirstLineAsContentValues(cursor);
+        } finally {
+            cursor.close();
+        }
     }
 
     /**
@@ -622,10 +632,15 @@ public class MetadataDbHelper extends SQLiteOpenHelper {
                 METADATA_TABLE_COLUMNS,
                 WORDLISTID_COLUMN + "= ? AND " + VERSION_COLUMN + "= ?",
                 new String[] { id, Integer.toString(version) }, null, null, null);
-        // This is a lookup by primary key, so there can't be more than one result.
-        final ContentValues result = getFirstLineAsContentValues(cursor);
-        cursor.close();
-        return result;
+        if (null == cursor) {
+            return null;
+        }
+        try {
+            // This is a lookup by primary key, so there can't be more than one result.
+            return getFirstLineAsContentValues(cursor);
+        } finally {
+            cursor.close();
+        }
     }
 
     /**
@@ -641,10 +656,15 @@ public class MetadataDbHelper extends SQLiteOpenHelper {
                 METADATA_TABLE_COLUMNS,
                 WORDLISTID_COLUMN + "= ?",
                 new String[] { id }, null, null, VERSION_COLUMN + " DESC", "1");
-        // This is a lookup by primary key, so there can't be more than one result.
-        final ContentValues result = getFirstLineAsContentValues(cursor);
-        cursor.close();
-        return result;
+        if (null == cursor) {
+            return null;
+        }
+        try {
+            // This is a lookup by primary key, so there can't be more than one result.
+            return getFirstLineAsContentValues(cursor);
+        } finally {
+            cursor.close();
+        }
     }
 
     /**