Qitmeer/qitmeer: core/blockdag/hashset.go; 5 LoC

Found a possible issue in [Qitmeer/qitmeer](https://www.github.com/Qitmeer/qitmeer) at [core/blockdag/hashset.go](https://github.com/Qitmeer/qitmeer/blob/43dfe070ff5ab00d4bf42ca540b524eaf99db0b3/core/blockdag/hashset.go#L78-L82)

Below is the message reported by the analyzer for this snippet of code. Beware that the analyzer only reports the first issue it finds, so please do not limit your consideration to the contents of the below message.

> function call at line 80 may store a reference to k

[Click here to see the code in its original context.](https://github.com/Qitmeer/qitmeer/blob/43dfe070ff5ab00d4bf42ca540b524eaf99db0b3/core/blockdag/hashset.go#L78-L82)

Click here to show the 5 line(s) of Go which triggered the analyzer.

```go
for k := range other.GetMap() {
if s.Has(&k) {
result.Add(&k)
}
}

```

Click here to show extra information the analyzer produced.

```
The following graphviz dot graph describes paths through the callgraph that could lead to a function which writes a pointer argument:
digraph G {
"(Add, 1)" -> {}
}

No path was found through the callgraph that could lead to a function which passes a pointer to third-party code.

```

Leave a reaction on this issue to contribute to the project by classifying this instance as a **Bug** :-1:, **Mitigated** :+1:, or **Desirable Behavior** :rocket:
See the descriptions of the classifications [here](https://github.com/github-vet/rangeclosure-findings#how-can-i-help) for more information.

commit ID: 43dfe070ff5ab00d4bf42ca540b524eaf99db0b3

Start by reading core/blockdag/hashset.go at lines 78-82 and the linked analyzer report. Trace how result.Add receives the range variable reference and determine whether the reported behavior is a real bug, mitigated, or desirable; done means recording the appropriate classification with evidence from the surrounding code.

Written by the indexing model from the issue text.