SERVER-652 unset/array sets value to null, which makes more sense

mongodb · Mar 3, 2010 · 4461c46 · 4461c46
1 parent 09b1285
commit 4461c46
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Showing 3 changed files with 28 additions and 7 deletions.
diff --git a/db/jsobj.h b/db/jsobj.h
@@ -1664,11 +1664,15 @@ namespace mongo {
             _b.appendAs(e, num().c_str());
             return *this;
         }
-
+        
         template <typename T>
         BSONArrayBuilder& operator<<(const T& x){
             return append(x);
         }
+
+        void appendNull() {
+            _b.appendNull(num().c_str());
+        }
 
         BSONArray arr(){ return BSONArray(_b.obj()); }
 
@@ -1705,7 +1709,7 @@ namespace mongo {
         void fill( const char *name ) {
             char *r;
             int n = strtol( name, &r, 10 );
-            uassert( 13047, "can't append to array using string field name", !*r );
+            uassert( 13048, "can't append to array using string field name", !*r );
             while( _i < n )
                 append( nullElt() );
         }

diff --git a/db/update.cpp b/db/update.cpp
@@ -67,6 +67,15 @@ namespace mongo {
         ms.appendIncValue( bb );
     }
 
+    template< class Builder >
+    void appendUnset( Builder &b ) {
+    }
+
+    template<>
+    void appendUnset( BSONArrayBuilder &b ) {
+        b.appendNull();
+    }
+
     template< class Builder >
     void Mod::apply( Builder& b , BSONElement in , ModState& ms ) const {
         switch ( op ){
@@ -83,7 +92,7 @@ namespace mongo {
         }
 
         case UNSET: {
-            //Explicit NOOP
+            appendUnset( b );
             break;
         }
 

diff --git a/jstests/unset2.js b/jstests/unset2.js
@@ -3,13 +3,21 @@ t.drop();
 
 t.save( {a:["a","b","c","d"]} );
 t.update( {}, {$unset:{"a.3":1}} );
-assert.eq( ["a","b","c"], t.findOne().a );
+assert.eq( ["a","b","c",null], t.findOne().a );
 t.update( {}, {$unset:{"a.1":1}} );
-assert.eq( ["a","c"], t.findOne().a );
+assert.eq( ["a",null,"c",null], t.findOne().a );
 t.update( {}, {$unset:{"a.0":1}} );
-assert.eq( ["c"], t.findOne().a );
+assert.eq( [null,null,"c",null], t.findOne().a );
+t.update( {}, {$unset:{"a.4":1}} );
+assert.eq( [null,null,"c",null], t.findOne().a ); // no change
 
 t.drop();
 t.save( {a:["a","b","c","d","e"]} );
 t.update( {}, {$unset:{"a.2":1},$set:{"a.3":3,"a.4":4,"a.5":5}} );
-assert.eq( ["a","b",3,4,5], t.findOne().a );
+assert.eq( ["a","b",null,3,4,5], t.findOne().a );
+
+t.drop();
+t.save( {a:["a","b","c","d","e"]} );
+t.update( {}, {$unset:{"a.2":1},$set:{"a.2":4}} );
+assert( db.getLastError() );
+assert.eq( ["a","b","c","d","e"], t.findOne().a );