863176 - Extra space at the end of a PDF file in the PDF Viewer with high resolution display

Status: RESOLVED DUPLICATE of bug 826938

(Firefox :: PDF Viewer, defect)

Description

[Loic]

Attachment: Screenshot FF23 on Win 7

Computer: screen 1920 x 1080 with zoom at 125%

STR:
1) Open a PDF sample like http://excerpts.numilog.com/books/2297001363.pdf
2) Scroll to the end of the PDF

Result:
Observe the unnecessary extra space.

Regression range:
m-c
good=2013-03-14
bad=2013-03-15
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=b672877ed046&tochange=0f7261e288f2

Suspected bug:
Jonathan Kew — bug 844604 - default to auto devPixelsPerPx setting on windows. r=jimm

Comment 1

[Greg Edwards]

Dupe of Bug 826938 ?

Comment 2

[Loic]

Yes, but bug 826938 is about Mac OSX (so the regressed bug is probably earlier in the year).

Comment 3

[Greg Edwards]

The Windows regression is just because we enabled HiDPI support at a later date than on OSX.

Comment 4

[Loic]

Ok, so duped, thanks.

Comment 5

[Brendan Dahl [:bdahl]]

Attachment: transform

On highdpi screens we create an extra large canvas and then scale the canvas down with a css transforms to improve the quality.  The extra space is due to the handling of the scaling and calculating heights.  I'm not exactly sure what the correct handling of this is since IE/Chrome/Firefox all have different results for the attachment (a highdpi screen is NOT needed to see the issues).

As a temporary workaround we can probably wrap the canvas in a div and hide the overflow, but we may want to investigate how this should be properly handled in another bug. I'll look into this tomorrow.