User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0 Build ID: 20170504105526 Steps to reproduce: I was using <tbody> element to add borders to a simple datagrid build using tables. Then I wanted to disable borders on a nested table, but I forgot how I applied them. So I tried using developer tools to check which elements have the actual borders (table, tbody, tr or td). I made a simple demo: https://jsfiddle.net/tracgb5s/ try to inspect the nested table's <tbody> element. Actual results: The box model preview shows that the <table> element has left and top borders visible and some <td> elements have bottom and right borders visible. <tbody> has no border. Expected results: It should display 1px border on the <tbody> element. Looks like there is some borders magic going on here, which is understandable, but the box model should display the CSS values, not the calculated ones. Chrome's box model preview shows correct values.
Component: Untriaged → Layout: Tables
Product: Firefox → Core
Confirmed the bug is existing in Nightly58. Chrome provides the result as reporter expected.
Status: UNCONFIRMED → NEW
status-firefox58: --- → affected
Ever confirmed: true
Priority: -- → P3
You need to log in before you can comment on or make changes to this bug.