go vet: possible misuse of unsafe.Pointer

[dtbartle]

When running go vet ./... I see a few errors that should be fixed:

./sqlite3.go:476:63: possible misuse of unsafe.Pointer
./sqlite3.go:494:67: possible misuse of unsafe.Pointer
./sqlite3.go:507:71: possible misuse of unsafe.Pointer
./sqlite3.go:524:67: possible misuse of unsafe.Pointer
./sqlite3.go:538:70: possible misuse of unsafe.Pointer

[rittneje]

It looks like these are all flagging uses of the newHandle function, which indeed violates the rules about uintptr to unsafe.Pointer conversions. In particular, it returns an incrementing counter and then tries to treat it as a pointer, which I believe has the capacity to really confuse the garbage collector, or worse.

https://golang.org/pkg/unsafe/#Pointer

Conversion of a uintptr back to Pointer is not valid in general.

A uintptr is an integer, not a reference. Converting a Pointer to a uintptr creates an integer value with no pointer semantics. Even if a uintptr holds the address of some object, the garbage collector will not update that uintptr's value if the object moves, nor will that uintptr keep the object from being reclaimed.

This function ought to be replaced with a compliant implementation, like this.