Borders of <select> drop down are incorrectly rendered (missing or too thick) in different situations




10 years ago
2 years ago


(Reporter: hello, Unassigned)


(Blocks 1 bug, {testcase})

Dependency tree / graph

Firefox Tracking Flags

(Not tracked)



(5 attachments)



10 years ago
User-Agent:       Opera/9.80 (Windows NT 5.2; U; en) Presto/2.2.15 Version/10.10
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US; rv: Gecko/20091221 Firefox/3.5.7 (.NET CLR 3.5.30729)

See the attached screenshot and test case HTML.

I'm using system defaults for the test case. If at least one of the styles (width or parent margin) are removed - the border is drawn.

It seems that this is due to some rounding error, because I'm defining the sizes in ems - I don't think it happens when integer px values are used.

On the website I'm working on, there are more such cases - it only happens on certain combinations. The only viable workaround is to use px instead of em.

Reproducible: Always

Steps to Reproduce:
Test case attached.
Actual Results:  
The right border does not appear, when the select is expanded (see the screenshot - it shows the incorrect and correct versions).

I think that these bugs are related:

The bug is also present in Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US; rv: Gecko/2009070611 Firefox/3.0.12 (.NET CLR 3.5.30729) for the same file.

Comment 1

10 years ago
Posted file Test case (Win)

Comment 2

10 years ago
Posted image Screenshot (Win)

Comment 3

10 years ago
Posted file Testcase (Mac)
The same can be witnessed on Mac, if the border: 1px solid; is set and width is adjusted.

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6

Comment 4

10 years ago
Also reproducible on 3.6

Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6
Version: unspecified → 3.6 Branch
I can indeed reproduce this with Firefox 3.6 but it is fixed on trunk:
I see this with SeaMonkey 2.1 Beta 1


9 years ago
Component: General → Layout: Form Controls
Product: Firefox → Core
QA Contact: general → layout.form-controls
Version: 3.6 Branch → unspecified


9 years ago
Keywords: testcase

Comment 7

9 years ago
Posted image issue in XUL
Confirming on websites but it happens also in XUL in 4.0b9pre20110110
I can confirm that this also happens on Firefox 36.0a1 (2014-11-27) + Win7 64-bit.

Ever confirmed: true
OS: Windows Server 2003 → Windows 7
Hardware: x86 → x86_64
Version: unspecified → Trunk
See Also: → 527676

Comment 10

4 years ago
I can confirm that this also happens on Firefox 37.0.1 + Win7 64-bit.

Duplicate of this bug: 1010703


4 years ago
See Also: → 429302
Duplicate of this bug: 527676
Duplicate of this bug: 994923
Duplicate of this bug: 924068
Severity: trivial → normal
OS: Windows 7 → All
Hardware: x86_64 → All
Summary: <select> right border not drawn upon certain non-integer width/parent margin combinations → Borders of <select> drop down are incorrectly rendered (missing or too thick) in different situations
Duplicate of this bug: 492718
URL: 402625
See Also: 527676
From the duplicate bug reports this happens:
- independently from HWA being enabled
- on different OSs (confirmed on Windows and OS X)
- on different borders

and is related to the drop-down list not being rendered using the native appearance (bug 402625).

URL: 402625
See Also: → 402625


3 years ago
Blocks: 1230801
On Windows 10 I cannot reproduce this issue anymore. Is that still the case on other OSs?

Flags: needinfo?(mozilla)
Flags: needinfo?(hello)

Comment 18

2 years ago
The related Bootstrap issue was . Affected OS(es) unclear.
Unfortunately there was no feedback from the initial reporter. Reading through the comments again I saw that at least Windows 7 is affected. Anybody able to clarify whether current macOS versions are affected?

Flags: needinfo?(mozilla)
Flags: needinfo?(hello)
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