Make findAndModify work when _id is removed in projection SERVER-2626

mongodb · May 31, 2011 · c117c4c · c117c4c
1 parent acc0592
commit c117c4c
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diff --git a/db/commands/find_and_modify.cpp b/db/commands/find_and_modify.cpp
@@ -53,6 +53,13 @@ namespace mongo {
             BSONObj fieldsHolder (cmdObj.getObjectField("fields"));
             const BSONObj* fields = (fieldsHolder.isEmpty() ? NULL : &fieldsHolder);
 
+            Projection projection;
+            if (fields) {
+                projection.init(fieldsHolder);
+                if (!projection.includeID())
+                    fields = NULL; // do projection in post-processing
+            }
+
             BSONObj out = db.findOne(ns, q, fields);
             if (out.isEmpty()) {
                 if (!upsert) {
@@ -131,6 +138,11 @@ namespace mongo {
                 }
             }
 
+            if (!fieldsHolder.isEmpty() && !fields){
+                // we need to run projection but haven't yet
+                out = projection.transform(out);
+            }
+
             result.append("value", out);
 
             return true;

diff --git a/db/projection.h b/db/projection.h
@@ -94,6 +94,8 @@ namespace mongo {
          */
         KeyOnly* checkKey( const BSONObj& keyPattern ) const;
 
+        bool includeID() const { return _includeID; }
+
     private:
 
         /**

diff --git a/jstests/find_and_modify2.js b/jstests/find_and_modify2.js
@@ -8,3 +8,9 @@ assert.eq(out, {_id:1, i:1});
 
 out = t.findAndModify({update: {$inc: {i:1}}, fields: {i:0}});
 assert.eq(out, {_id:1, j:0});
+
+out = t.findAndModify({update: {$inc: {i:1}}, fields: {_id:0, j:1}});
+assert.eq(out, {j:0});
+
+out = t.findAndModify({update: {$inc: {i:1}}, fields: {_id:0, j:1}, 'new': true});
+assert.eq(out, {j:0});