"Maximum call stack size exceeded" when using v-show on a component using transition as root element

[schnuet]

Version

3.2.29

Reproduction link

sfc.vuejs.org/

Steps to reproduce

1. Open the repro.
2. Wait. (up to 3 minutes)

What is expected?

The code should run indefinitely, without warnings.

What is actually happening?

After (around) three minutes, the console is flooded with "Maximum call stack size exceeded" errors and the browser slows down to a crawl. This gets worse the longer the page is left open.

---

I had refactored a lot of my code to use embedded transitions in components and forgot remove one place where I used v-show instead of the new "visible" prop. That crashed my app after a while.

[lidlanca]

rawSlot after an update will already be normalized.
resulting in a normalized slot function being normalized over and over.

with enough updates calling the normalized slot will reach the max stack size

core/packages/runtime-core/src/componentSlots.ts

Lines 61 to 79 in 644971e

	const normalizeSlot = (
	key: string,
	rawSlot: Function,
	ctx: ComponentInternalInstance | null | undefined
	): Slot => {
	const normalized = withCtx((...args: any[]) => {
	if (__DEV__ && currentInstance) {
	warn(
	`Slot "${key}" invoked outside of the render function: ` +
	`this will not track dependencies used in the slot. ` +
	`Invoke the slot function inside the render function instead.`
	)
	}
	return normalizeSlotValue(rawSlot(...args))
	}, ctx) as Slot
	// NOT a compiled slot
	;(normalized as ContextualRenderFn)._c = false
	return normalized
	}

this patch will fix this bug, but perhaps there might be an higher level fix.

const normalizeSlot = (key, rawSlot, ctx) => {

    if(rawSlot && rawSlot._c === false) {
        // already normalized  
        return rawSlot 
    }
    const normalized = withCtx((...args) => {
     ...
    }, ctx);
    normalized._c = false;
    return normalized;
};

[edison1105]

@lidlanca
should be

if(rawSlot._n) {
	// already normalized  
	 return rawSlot 
}

[lidlanca]

@edison1105

nice, so withCtx actually adds the _n marking, I missed that.

core/packages/runtime-core/src/componentRenderContext.ts

Lines 105 to 106 in 9c304bf

	// mark normalized to avoid duplicated wrapping
	renderFnWithContext._n = true