ExpressionToHashedIndexKey::_doAddDependencies() doesn't add the dependencies of its _children[0] expression. This causes the $project stage to incorrectly treat the field path expression as a missing value and hash it to the value of an explicit null value.
void ExpressionToHashedIndexKey::_doAddDependencies(DepsTracker* deps) const { // Nothing to do }
- is related to
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                    SERVER-49214 Add $toHashedIndexKey expression -         
- Closed
 
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- related to
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                    SERVER-58048 Resharding's initial split points for hashed shard keys don't match the sampled values -         
- Closed
 
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