Bug 249076 – Using @media to switch grid-column causes crash

• Status: NEW
• Component: Layout and Rendering

[Wenzel Massag]

# The issue:
When I resize the window across the threshold in .classB (in the example it is 1280px) in either direction, the page crashes and reloads.

## Description of the CS below:
I use a CSS variable to define the number of columns in my grid based on a media query. I also use media queries to switch between different notations of the grid-column shorthand.


## CSS:
```CSS
.classA {
  --number-of-columns: 4;
  display: grid;
  grid-template-columns: repeat(var(--number-of-columns), 1fr);
  column-gap: 16px;
}

@media (min-width: 744px) {
  .classA {
    --number-of-columns: 12;
    column-gap: 32px;
  }
}

.classB {
  grid-column: span var(--number-of-columns);
}

@media (min-width: 1280px) {
  .classB {
    grid-column: 4 / 10;
  }
}
```

[Alexey Proskuryakov]

Thank you for the report! Could you please attach a complete test case? Just putting this stylesheet doesn't reproduce the crash, unsurprisingly.

[Radar WebKit Bug Importer]

<rdar://problem/103482850>