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Diffstat (limited to 'core/java/android/content/ContentProvider.java')
| -rw-r--r-- | core/java/android/content/ContentProvider.java | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/core/java/android/content/ContentProvider.java b/core/java/android/content/ContentProvider.java index fd65d56..72e701d 100644 --- a/core/java/android/content/ContentProvider.java +++ b/core/java/android/content/ContentProvider.java @@ -211,7 +211,27 @@ public abstract class ContentProvider implements ComponentCallbacks2 { // We do not call ContentProvider#query with a modified where clause since // the implementation is not guaranteed to be backed by a SQL database, hence // it may not handle properly the tautology where clause we would have created. - return new MatrixCursor(projection, 0); + if (projection != null) { + return new MatrixCursor(projection, 0); + } + + // Null projection means all columns but we have no idea which they are. + // However, the caller may be expecting to access them my index. Hence, + // we have to execute the query as if allowed to get a cursor with the + // columns. We then use the column names to return an empty cursor. + Cursor cursor = ContentProvider.this.query(uri, projection, selection, + selectionArgs, sortOrder, CancellationSignal.fromTransport( + cancellationSignal)); + + // Create a projection for all columns. + final int columnCount = cursor.getCount(); + String[] allColumns = new String[columnCount]; + for (int i = 0; i < columnCount; i++) { + allColumns[i] = cursor.getColumnName(i); + } + + // Return an empty cursor for all columns. + return new MatrixCursor(allColumns, 0); } final String original = setCallingPackage(callingPkg); try { |