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Bug 15743 - Margin collapsing: editorial issues
Summary: Margin collapsing: editorial issues
Status: NEW
Alias: None
Product: CSS
Classification: Unclassified
Component: CSS Level 2 (show other bugs)
Version: unspecified
Hardware: All Windows 3.1
: P2 normal
Target Milestone: ---
Assignee: Bert Bos
QA Contact: public-css-bugzilla
Depends on:
Reported: 2012-01-27 17:54 UTC by Anton P
Modified: 2012-12-04 00:53 UTC (History)
0 users

See Also:


Description Anton P 2012-01-27 17:54:57 UTC
Reported by Anton Prowse


8.3.1 (Collapsing margins) says in a note listing various practical implications of the margin collapsing rules:

  # A box's own margins collapse if the 'min-height' property is zero, and
  # it has neither top or bottom borders nor top or bottom padding, and it
  # has a 'height' of either 0 or 'auto', and it does not contain a line box,
  # and all of its in-flow children's margins (if any) collapse.

The prose is gramatically incorrect since "(if any)" qualifies children, not margins.

s/all of its in-flow children's margins (if any) collapse/the margins of all of its in-flow children (if any) collapse/



Most list items in the note referred to above discuss boxes, but two of them discuss elements.  Perhaps those two could be changed to discuss boxes, to give more consistency to the note.



The note referred to above includes:

  # * The bottom margin of an in-flow block box with a 'height' of
  # 'auto' and a 'min-height' of zero collapses with its last in-flow
  # block-level child's bottom margin if the box has no bottom padding
  # and no bottom border and the child's bottom margin does not
  # collapse with a top margin that has clearance.

There's no such thing as "a top margin that has clearance".  Possible solution:

  |                [...] and the child's bottom margin does not
  | collapse with the top margin of an element (possibly itself) that
  | has clearance."