SERVER-4975 test

jstests/coveredIndex3.js

@@ -0,0 +1,54 @@
+// Check proper covered index handling when query and processGetMore yield.
+// SERVER-4975
+
+if ( 0 ) { // SERVER-4975
+
+t = db.jstests_coveredIndex3;
+t2 = db.jstests_coveredIndex3_other;
+t.drop();
+t2.drop();
+
+function doTest( batchSize ) {
+
+    // Insert an array, which will make the { a:1 } index multikey and should disable covered index
+    // matching.
+    p1 = startParallelShell(
+                           'for( i = 0; i < 60; ++i ) { \
+                               db.jstests_coveredIndex3.save( { a:[ 2000, 2001 ] } ); \
+                               sleep( 300 ); \
+                           }'
+                           );
+
+    // Frequent writes cause the find operation to yield.
+    p2 = startParallelShell(
+                            'for( i = 0; i < 1800; ++i ) { \
+                            db.jstests_coveredIndex3_other.save( {} ); \
+                            sleep( 10 ); \
+                            }'
+                            );
+
+    for( i = 0; i < 30; ++i ) {
+        t.drop();
+        t.ensureIndex( { a:1 } );
+
+        for( j = 0; j < 1000; ++j ) {
+            t.save( { a:j } );
+        }
+
+        c = t.find( {}, { _id:0, a:1 } ).hint( { a:1 } ).batchSize( batchSize );
+        while( c.hasNext() ) {
+            o = c.next();
+            // If o contains a high numeric 'a' value, it must come from an array saved in p1.
+            assert( !( o.a > 1500 ), 'improper object returned ' + tojson( o ) );
+        }
+    }
+
+    p1();
+    p2();
+
+}
+
+doTest( 2000 ); // Test query.
+doTest( 500 ); // Try to test getMore - not clear if this will actually trigger the getMore issue.
+
+}