Fix button with icons but empty slot rendered as square button

[ghabriel25]

Summary

Fix flux button with icons but no slot content rendered as square button

Problem

Buttons with both icon and icon:trailing but no text content were incorrectly rendered as square buttons when Blaze was disabled/enabled.

This happens because an empty/whitespace-only slot is treated as empty by the compiled view, causing $square to default to true. As a result, the button receives the square styling (w-8 for small button) and the two icons lose their expected spacing and overlap.

Solution

Only default the button to square when the slot is empty and the button does not contain both a leading and trailing icon.

This preserves the existing square-button behavior for icon-only buttons while ensuring buttons containing two icons are rendered with the correct spacing, regardless of whether Blaze is enabled.

Before

$square ??= $slot->isEmpty();

After

$square ??= $slot->isEmpty() && ! ($iconLeading && $iconTrailing);

Setup

<flux:main class="flex gap-6">
    <flux:button wire:click="save" variant="outline" icon="briefcase" icon:trailing="chevron-down"> </flux:button>
    <flux:button wire:click="save" variant="outline" icon="briefcase" icon:trailing="chevron-down" :square="false" />
    <flux:button wire:click="save" variant="outline" icon="briefcase" icon:trailing="chevron-down" />
    <flux:button wire:click="save" variant="outline" icon="briefcase" icon:trailing="chevron-down">Test</flux:button>
    <flux:button.group>
        <flux:button>Save</flux:button>
        <flux:button icon="chevron-down" />
    </flux:button.group>
    <flux:button.group>
        <flux:button icon="pencil-square" />
        <flux:button>Edit</flux:button>
    </flux:button.group>
    <flux:button.group>
        <flux:button icon="magnifying-glass" />
        <flux:button>Options</flux:button>
        <flux:button icon="chevron-down" />
    </flux:button.group>
</flux:main>

Note

Notice that the first button with whitespace slot rendered slightly different when Blaze disabled and enabled. It seems Blaze treat whitespace differently therefore I'll just keep it as it is.

Blaze Off

Before:

After:

Blaze On

Before:

After:

Related PR: livewire/blaze#209
Fixes #2816