Scalar interval block: unbounded value causes main-thread hang (missing magnitude validation)

[bhuvan-somisetty]

Description

The scalar interval (+/-) block (Intervals palette) validates its argument's type but never its magnitude.

ScalarIntervalBlock.flow() in js/blocks/IntervalsBlocks.js:

flow(args, logo, turtle, blk) {
    if (args[1] === undefined) return;

    Singer.IntervalsActions.setScalarInterval(args[0], turtle, blk);

    return [args[1], 1];
}

passes args[0] straight through to setScalarInterval() (js/turtleactions/IntervalsActions.js:383), which only checks that the value is non-null and a number:

static setScalarInterval(value, turtle, blk) {
    let arg = value;
    if (arg === null || typeof arg !== "number") {
        activity.errorMsg(NOINPUTERRORMSG, blk);
        arg = 1;
    }
    ...
    const i = arg > 0 ? Math.floor(arg) : Math.ceil(arg);
    tur.singer.intervals.push(i);
    ...
}

No upper/lower bound is applied before the value is pushed onto tur.singer.intervals.

That value is then read back in GetNotesForInterval() (js/utils/musicutils.js:5320):

if (intervals && intervals.length) {
    octave = Math.floor(intervals[0] / 7);
}

and consumed by a synchronous loop in GetIntervalNumber() (js/turtleactions/IntervalsActions.js:116-119):

while (octave > 0) {
    totalIntervals += temperamentLength;
    octave--;
}

octave scales linearly with the raw scalar-interval value, so a single large (but finite) input drives this loop for however many iterations that implies — with no error message and no way to recover short of a forced tab close.

GetIntervalNumber() is reached synchronously and inline: it's called directly from the interval number and current interval reporter blocks' arg() methods (js/blocks/IntervalsBlocks.js), which are evaluated during flow, not scheduled/queued.

Expected Behavior

Either the block clamps/rejects out-of-range values with a clear error message (similar to how the Arc block's angle/radius arguments are bound-checked), or the underlying loop is otherwise protected from an unbounded iteration count.

Screenshots

N/A — this is a hang/freeze, not a visual defect.

How to Reproduce

1. Add a "scalar interval (+/-)" block with a large numeric input (e.g. 999999999).
2. Nest an "interval number" (or "current interval") reporter block inside it, feeding a print block.
3. Run the project.

Console log Errors

None — the tab freezes silently; no error is logged or shown to the user.

Environment

• Operating System: Windows
• Browser (if applicable): N/A (reproducible in any browser)
• Version of Software/Project: current master

Checklist

• I have read and followed the project's code of conduct.
• I have searched for similar issues before creating this one.
• I have provided all the necessary information to understand and reproduce the issue.
• I am willing to contribute to the resolution of this issue.