Bug 18291 – vertical dotted line not seen. due to less pixel value of border:left

• Component: CSS
• Status: RESOLVED INVALID

[jasneet]

I Steps:
Go to 
http://recipe.aol.com/recipe/cajun-chicken-pasta/2071
Scroll to the middle of the page.
Click on tab "Save to my Cookbook" in the center column

II Issue:
Vertical dotted line is not seen which divides columns AOL users and New Users.

III Conclusion:
.atunauthlo{border-left:0.0714em dotted #d8c9bc;}
if i change border-left:0.0714em to border-left:0.0914em then dotted line appears.

IV Other browsers:
IE7: ok
FF3: ok
Opera9.24: ok

V Nightly tested: 31446

[jasneet]

Created attachment 20302 [details]
screenshot

[jasneet]

Created attachment 20303 [details]
reduction

[Tab Atkins]

Not a bug.  Precise rounding behavior is undefined in CSS.  The referenced page no longer has a relevant example, but if we assume that the testcase is exercising the same code, then the "problem" is that, with a font-size of 13px, a border of 0.0714em is rounding to zero.  It computes to .93px, which is allowed to be rounded down to 0.

(It's clear that the referenced page actually *wanted* a border of 1px, but dogmatically used the em unit out of some misguided attempt to be "scalable".  Unfortunately, they set the value to 1/14, which was either a mistake or a leftover from a time when the font-size was 14px.)