842112 - Inconsistencies in "Prevent styling that would change the type of frame we construct"

Status: NEW

(Core :: Layout: Form Controls, defect)

Description

[Jesse Ruderman]

http://hg.mozilla.org/mozilla-central/file/default/layout/style/forms.css

::-moz-progress-bar {
  /* Prevent styling that would change the type of frame we construct. */
  display: inline-block ! important;
  float: none ! important;
  position: static ! important;
  overflow: visible ! important;
  -moz-box-sizing: border-box ! important;
}

Assuming these 5 are exactly what are needed,

* ::-moz-meter-bar   is missing -moz-box-sizing and a comment wording fix
* ::-moz-range-track is missing -moz-box-sizing and overflow
* ::-moz-range-thumb is missing -moz-box-sizing and overflow

(Is this needed for safety?  Are there corresponding assertions in C++?)

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

From a very quick look through the list, properties that can affect the type of frame constructed are:

-moz-binding
position
display
float
overflow (and, when overflow!=visible, resize)
direction (hopefully only changes type for inlines)
-moz-column-width
-moz-column-count

The -moz-box-sizing might be important, but it's not about the type of frame we construct.

Comment 2

[Mounir Lamouri (:mounir)]

IIRC, those !important have been set because changing them could lead to crashes, assertions or unexpected behaviour.