jarodvip/syncthing: lib/db/instance.go; 49 LoC

Found a possible issue in [jarodvip/syncthing](https://www.github.com/jarodvip/syncthing) at [lib/db/instance.go](https://github.com/jarodvip/syncthing/blob/9084510e1b12a3ed93abfe933da9a3a828b509f0/lib/db/instance.go#L71-L119)

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.

>

[Click here to see the code in its original context.](https://github.com/jarodvip/syncthing/blob/9084510e1b12a3ed93abfe933da9a3a828b509f0/lib/db/instance.go#L71-L119)

Click here to show the 49 line(s) of Go which triggered the analyzer.

```go
for _, f := range fs {
name := []byte(f.Name)
dk = db.keyer.GenerateDeviceFileKey(dk, folder, protocol.LocalDeviceID[:], name)

ef, ok := t.getFileByKey(dk)
if ok && unchanged(f, ef) {
continue
}

if ok {
if !ef.IsDirectory() && !ef.IsDeleted() && !ef.IsInvalid() {
for _, block := range ef.Blocks {
keyBuf = db.keyer.GenerateBlockMapKey(keyBuf, folder, block.Hash, name)
t.Delete(keyBuf)
}
}

keyBuf = db.keyer.GenerateSequenceKey(keyBuf, folder, ef.SequenceNo())
t.Delete(keyBuf)
l.Debugf("removing sequence; folder=%q sequence=%v %v", folder, ef.SequenceNo(), ef.FileName())
}

f.Sequence = meta.nextLocalSeq()

if ok {
meta.removeFile(protocol.LocalDeviceID, ef)
}
meta.addFile(protocol.LocalDeviceID, f)

l.Debugf("insert (local); folder=%q %v", folder, f)
t.Put(dk, mustMarshal(&f))

gk = db.keyer.GenerateGlobalVersionKey(gk, folder, []byte(f.Name))
keyBuf, _ = t.updateGlobal(gk, keyBuf, folder, protocol.LocalDeviceID[:], f, meta)

keyBuf = db.keyer.GenerateSequenceKey(keyBuf, folder, f.Sequence)
t.Put(keyBuf, dk)
l.Debugf("adding sequence; folder=%q sequence=%v %v", folder, f.Sequence, f.Name)

if !f.IsDirectory() && !f.IsDeleted() && !f.IsInvalid() {
for i, block := range f.Blocks {
binary.BigEndian.PutUint32(blockBuf, uint32(i))
keyBuf = db.keyer.GenerateBlockMapKey(keyBuf, folder, block.Hash, name)
t.Put(keyBuf, blockBuf)
}
}

t.checkFlush()
}

```

Click here to show extra information the analyzer produced.

```
No path was found through the callgraph that could lead to a function which writes a pointer argument.

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

root signature {mustMarshal 1} was not found in the callgraph; reference was passed directly 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: 9084510e1b12a3ed93abfe933da9a3a828b509f0

Inspect lib/db/instance.go around lines 71-119 and read the linked analyzer context first. Determine whether the reported range-loop or pointer behavior can occur in this path, then confirm the result with an appropriate regression test; done means the finding is reproduced and corrected, or documented as non-bug behavior.

Written by the indexing model from the issue text.