Serialize "0" as "0px" for lengths instead of "0pt"

RESOLVED FIXED in mozilla13



11 years ago
7 years ago


(Reporter: jruderman, Assigned: ayg)


Bug Flags:
in-testsuite +

Firefox Tracking Flags

(Not tracked)



(2 attachments, 2 obsolete attachments)



11 years ago
Created attachment 278463 [details]

It would be nice if "width: 0" would stay as "0" instead of becoming "0pt" when serialized.  I rarely use pt units so it's strange to see them appear unnecessarily.
IE7/Windows gives 0px
Opera 9.23/Linux gives 0
Konqueror gives 0px

I agree that 0 is better style; not sure if I want to make the switch at this point in the cycle.  Nobody else gives pt, though.
We could make a simple fix in nsCSSDeclaration::AppendCSSValueToString , but it would be nice to round-trip the unit as specified.  We currently store 0s as various default units in CSSParserImpl::TranslateDimension; the way to round-trip properly would involve adding a new unit for them and making sure that unit was handled appropriately.
I think this bug should really be about round-tripping what the author specified rather than converting other values to 0, though.

(The reason for points as the default in TranslateDimension may have been that points were cheaper to compute back when we used twips; that's no longer the case following bug 177805.)


9 years ago
Duplicate of this bug: 516442


9 years ago
OS: Mac OS X → All
Hardware: x86 → All

data:text/html,<!doctype html>
<script> = "0";
document.documentElement.textContent =

IE10 Developer Preview: 0px
mozilla-central:        0pt
Chrome 18 dev:          0px
Opera Next 12.00 alpha: 0px


"A length of zero is represented by the literal string "0px"."

Seems like "0px" is the winner here.  "0" makes more sense, but nobody does that right now, so it makes more sense to go with what everyone else does.
Created attachment 596762 [details] [diff] [review]
Patch v1

This serializes it as "0px", like the spec and other browsers.
Assignee: nobody → ayg
Attachment #596762 - Flags: review?(dbaron)
Whiteboard: [autoland]


7 years ago
Whiteboard: [autoland] → [autoland-in-queue]

Comment 7

7 years ago
Autoland Patchset:
	Patches: 596762
	Branch: mozilla-central => try
Try run started, revision 56185fcd57d1. To cancel or monitor the job, see:
Comment on attachment 596762 [details] [diff] [review]
Patch v1

>+// Bug 393910
>+p.setAttribute("style", "margin-left: 0");
>+is("margin-left"), "0px",
>+  "0 serializes to 0px");
> for (var test in tests) {

Could you put your insertion after the main for loop instead of before?

r=dbaron with that
Attachment #596762 - Flags: review?(dbaron) → review+
Created attachment 596770 [details] [diff] [review]
Patch v2
Attachment #596762 - Attachment is obsolete: true
Attachment #596770 - Flags: review?(dbaron)
Attachment #596770 - Flags: review?(dbaron) → review+

Comment 10

7 years ago
Try run for 56185fcd57d1 is complete.
Detailed breakdown of the results available here:
Results (out of 210 total builds):
    exception: 3
    success: 164
    warnings: 29
    failure: 14
Builds (or logs if builds failed) available at:


7 years ago
Whiteboard: [autoland-in-queue]
Created attachment 597038 [details] [diff] [review]
Patch v3, test failure fixed

There was a test I missed in content/base/, because I only tested layout/style/ locally.
Attachment #596770 - Attachment is obsolete: true
Attachment #597038 - Flags: review+
Keywords: testcase → checkin-needed
Summary: Output unitless zero for style.width ("0" instead of "0pt") → Serialize "0" as "0px" for lengths instead of "0pt"
Flags: in-testsuite+
Keywords: checkin-needed
Target Milestone: --- → mozilla13
Last Resolved: 7 years ago
Resolution: --- → FIXED
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