<table style="border-spacing: 50px"><tr><td colspan=2>long long text</td></tr><tr><td>lo</td><td>xt</td><tr></table> [long long text] [lo] [xt] While it looks like the spanning cell has to distribute all its spanning width, the border-spacing takes most of the space and no distribution is needed at all.
Created attachment 396890 [details] Patch
Committed r260337: <https://trac.webkit.org/changeset/260337> All reviewed patches have been landed. Closing bug and clearing flags on attachment 396890 [details].
<rdar://problem/62023939>