Attach (recommended) or Link to PDF file here:
http://education.ohio.gov/getattachment/Topics/Special-Education/Preschool-Special-Education/ETR-Preschool-Planning-Form.pdf.aspx

- Web browser and its version: Firefox 89.0.1
- Operating system and its version: Windows 10 10.0.19043.1052
- PDF.js version: commit 5d251a3a3e7bfaa8fbfa07f0b7f9901eb3f999d9
- Is a browser extension: No

Steps to reproduce the problem:
1. Enable XFA support
2. Open form

What is the expected behavior? (add screenshot)
Shapes stay inside table cells
![image](https://user-images.githubusercontent.com/7104454/122572782-1252a580-d01c-11eb-9d0f-5fed46d6f2fe.png)

What went wrong? (add screenshot)
Shapes fall outside cells (among other issues)
![image](https://user-images.githubusercontent.com/7104454/122572885-2d251a00-d01c-11eb-8863-fa3b9969f0ea.png)

numberInLine: 0,
      availableSpace: {
        width: Math.min(this.w || Infinity, availableSpace.width),
        height: Math.min(this.h || Infinity, availableSpace.height),
      },
      width: 0,
      height: 0,
      prevHeight: 0,
      currentWidth: 0,
    });
    const isSplittable = this[$isSplittable]();
    if (!isSplittable) {
      setFirstUnsplittable(this);
    }
    if (!checkDimensions(this, availableSpace)) {
      return HTMLResult.FAILURE;
    }
    availableSpace = {
      width: this.w === "" ? availableSpace.width : this.w,
      height: this.h === "" ? availableSpace.height : this.h,
    };
    const filter = new Set(["field"]);
    if (this.layout.includes("row")) {
      const columnWidths = this[$getSubformParent]().columnWidths;
      if (Array.isArray(columnWidths) && columnWidths.length > 0) {
        this[$extra].columnWidths = columnWidths;
        this[$extra].currentColumn = 0;
      }
    }
    const style = toStyle(