fix panic and filter on 'database/sql' package

[ldez]

Fix #3

[favonia]

Maybe also adding the following checking before var s string?

			if i >= len(n.Args) {
				return
			}

I know this is impossible for the current database/sql (if the program type checks), but I feel we should still check.

[1uf3]

In the golang, the definition of the variable is different between var s string and s := "AAAA"
this code is only checking s := "AAAA" case.

[favonia]

@lufeee No I was not talking about the variable s. Please keep that line as it is. I was proposing the following code, in addition to what @ldez what already did:

			// ...

			if i >= len(n.Args) {
				return
			}

			var s string
			switch arg := n.Args[i].(type) {

			// ...

The reason is that n.Args[i] will panic if i >= len(n.Args[i]). And the reason I propose putting the check before the line var s string is because the variable s is meaningful only later.

[ldez]

the check is at the beginning of the function.

[favonia]

Ah, sorry I somehow missed it.

[favonia]

CORRECTION: No, the check is still wrong...

[ldez]

FYI: my login is ldez not idez

I will take a look

[favonia]

@ldez I created the PR #8 with an example.

PS: Sorry I fixed the tagging.

[Hades32]

@lufeee

[1uf3]

@ldez Thanks for fixing this bug.
LGTM

[favonia]

The code does not fix all the problems because i could be 1 after checking len(n.Args) < 1. However, it is difficult to unmerge a PR, so let me start another PR.