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  2. SERVER-42151

$multiply with NaN operand violates commutativity

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      python buildscripts/resmoke.py --storageEngine wiredTiger --suites aggregation  repro_multiply.js
      repro_multiply.js
      assert.commandWorked(db.my_coll.insert({}));

assert.throws(() => db.my_coll.aggregate(
[{                                                                             
    "$project": {                                                                        
        "a": {                                                                           
                "$multiply": [                                                           
                    NaN,                                                                 
                    {                                                                    
                        "$const": NumberDecimal("1")                                     
                    }                                                                    
                ]                                                                        
        },
        _id: 0                                                                                
    }                                                                                    
}]));

let res = db.my_coll.aggregate(
[{                                                                             
    "$project": {                                                                        
        "a": {                                                                           
                "$multiply": [                                                                                                                            
                    {                                                                    
                        "$const": NumberDecimal("1")                                     
                    },
                    NaN                                                                    
                ]                                                                        
        },
        _id: 0                                                                                
    }                                                                                    
}]);
assert.neq(res, null);
      Show
      python buildscripts/resmoke.py --storageEngine wiredTiger --suites aggregation repro_multiply.js repro_multiply.js assert.commandWorked(db.my_coll.insert({})); assert. throws (() => db.my_coll.aggregate( [{ "$project" : { "a" : { "$multiply" : [ NaN, { "$ const " : NumberDecimal( "1" ) } ] }, _id: 0 } }])); let res = db.my_coll.aggregate( [{ "$project" : { "a" : { "$multiply" : [ { "$ const " : NumberDecimal( "1" ) }, NaN ] }, _id: 0 } }]); assert.neq(res, null );
    • Query 2019-08-26
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      When $multiply is evaluated, if an expression that evaluates to NaN is encountered first then the pipeline errors with the following message:

      Error: command failed: {
   	"ok" : 0,
   	"errmsg" : "Failed to optimize pipeline :: caused by :: Can't coerce out of range value nan to long",
   	"code" : 31109,
   	"codeName" : "Location31109"
   } : aggregate failed

      However if NaN is evaluated second, the command runs and returns results. This means that changing the order of the operands changes whether the command runs or errors, invalidating commutativity.

            Assignee:
            anton.korshunov@mongodb.com Anton Korshunov
            Reporter:
            claire.childs@mongodb.com Claire Childs (Inactive)
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              Created:
              Updated:
              Resolved: