1 files changed, 48 insertions, 0 deletions
diff --git a/jstests/orp.js b/jstests/orp.js
new file mode 100644
index 00000000000..94f53b506cc
--- /dev/null
+++ b/jstests/orp.js
@@ -0,0 +1,48 @@
+// Delete and update work properly when the document to be modified is the first of a new unindexed
+// $or clause.  SERVER-5198
+
+t = db.jstests_orp;
+t.drop();
+
+function verifyExpectedQueryPlan( query ) {
+    explain = t.find( query ).explain();
+    assert.eq( 'BtreeCursor a_1', explain.clauses[ 0 ].cursor );
+    assert.eq( 'BasicCursor', explain.clauses[ 1 ].cursor );
+}
+
+function checkAdvanceWithWriteOp( writeOp ) {
+    t.drop();
+   
+    for( i = 0; i < 120; ++i ) {
+        t.insert( { a:119-i, b:2 } );
+    }
+
+    t.ensureIndex( { a:1 } );
+
+    // The presence of an index on the b field causes the query below to generate query plans for
+    // each $or clause iteratively rather than run a simple unindexed query plan.
+    t.ensureIndex( { c:1, b:1 } );
+
+    // The cursors traversed for this $or query will be a:1, $natural:1.  The second clause will run
+    // as an unindexed scan because no index has b as its first field.  The a:119 document will
+    // be the last document of the first clause and the first document of the (unindexed) second
+    // clause.
+    query = { $or:[ { a:{ $gte:0 } }, { b:2 } ] };
+    verifyExpectedQueryPlan( query );
+    writeOp( query );
+    assert( !db.getLastError() );
+    assert.eq( 120, db.getLastErrorObj().n );
+}
+
+// Remove.
+checkAdvanceWithWriteOp( function( query ) { t.remove( query ); } );
+// The documents were removed.
+assert.eq( 0, t.count() );
+assert.eq( 0, t.find().itcount() );
+
+// Update - add a large field so the document will move.
+big = new Array( 10000 ).toString();
+checkAdvanceWithWriteOp( function( query ) { t.update( query, { $push:{ z:big } }, false,
+                                                      true ); } );
+// The documents were updated.
+assert.eq( 120, t.count( { z:{ $size:1 } } ) );