Integer parameters equal to 2^63 pass the range check in toInt and wrap to a negative number #3489

Describe the bug

toInt in pkg/github/params.go is documented to reject "values outside the int range", but its upper bound check compares against math.MaxInt as a float:

if f > math.MaxInt || f < math.MinInt {
    return 0, fmt.Errorf("numeric value out of int range: %v", f)
}
return int(f), nil

math.MaxInt (2^63 - 1) cannot be represented as a float64 and rounds up to exactly 2^63. A value of 2^63 is therefore not greater than the bound, passes the check, and int(f) on an out-of-range float is implementation-defined in Go. On amd64 it produces math.MinInt (-9223372036854775808).

Any value that parses to 2^63, including the integer 9223372036854775807 itself, is accepted without an error and becomes a large negative number. This affects every tool that reads integers through RequiredInt, OptionalIntParam, OptionalIntParamWithDefault and OptionalPaginationParams (for example issue_number, pull_number, page, perPage). toInt64 is not affected because it uses a round-trip check.

Affected version

main at 07e2466, built from source (Go toolchain from go.mod, linux/amd64).

Steps to reproduce the behavior

1. Add this test to pkg/github:

   package github
   
   import "testing"
   
   func TestToIntUpperBound(t *testing.T) {
       for _, v := range []any{"9223372036854775807", float64(9223372036854775807), "9223372036854775808", "1e19"} {
           n, err := OptionalIntParam(map[string]any{"pull_number": v}, "pull_number")
           t.Logf("%v -> %d, err=%v", v, n, err)
       }
   }

2. Run go test ./pkg/github -run TestToIntUpperBound -v.

Expected vs actual behavior

Expected: every value at or above 2^63 is rejected with numeric value out of int range, as 1e19 already is.

Actual:

9223372036854775807    -> -9223372036854775808, err=<nil>
9.223372036854776e+18  -> -9223372036854775808, err=<nil>
9223372036854775808    -> -9223372036854775808, err=<nil>
1e19                   -> 0, err=parameter pull_number is not a valid number: numeric value out of int range: 1e+19

The negative value is then sent on to the GitHub API (for example as a pull request number or page) instead of being rejected locally with a clear parameter error.

Logs

Not applicable; the output above is from the test.

Possible Solution

1. Make the upper bound exclusive at 2^63 (f >= -float64(math.MinInt)), or reuse the round-trip check that toInt64 already performs.
2. Add the boundary values above to the existing toInt tests.

if f >= -float64(math.MinInt) || f < float64(math.MinInt) {
    return 0, fmt.Errorf("numeric value out of int range: %v", f)
}
return int(f), nil

I'm happy to send a PR.