1465774 - [Ubuntu] Distorted content while scrolling inside a Pdf file in Print Preview (Landscape mode only)

Status: NEW

(Core :: Print Preview, defect, P4)

Description

[Anca Soncutean, Desktop QA]

[Affected versions]: 
- 60.0.1 (20180516032328)
- 61.0b10 (20180530184300)
- 62.0a1 (2018-05-30)

[Affected platforms]:
- Ubuntu 16.04 x64
- Ubuntu 14.04 x32

[Steps to reproduce]:
1. Launch Firefox
2. Open a .pdf file inside the browser
3. Go to Print Preview (File - Print Preview or Menu - Print)
4. Change the orientation mode to Landscape
5. Scroll down the page and observe the behavior

[Expected result]:
- The scrolling is smooth, there are no rendering issues.

[Actual result]:
- The content slides along with the scroll and part of it disappears in this process(https://drive.google.com/open?id=1yaxSHl_8iX-OSkqibSP6ShqV8PcGqx_0)

[Regression range]:
- I manage to reduce the regression range to the followings:
  Last good revision: c750a7de1194d71f2d2ef73f6a919d26b9640cae (2016-12-15)
  First bad revision: 63b447888a6469b9f6ae8f76ac5f0d7c6ea239da (2016-12-16)
  Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=c750a7de1194d71f2d2ef73f6a919d26b9640cae&tochange=63b447888a6469b9f6ae8f76ac5f0d7c6ea239da

[Additional Notes]:
- This issue is not reproducible in Portrait mode.
- This exactly behavior is not triggered on OS X and Windows platforms, but when in Landscape mode the bottom of the page is cut off (see bug 1430114).
- This behaviour can be observed, only when the scale is set to 100% or to “Shrink to Fit”.

Comment 1

[Anca Soncutean, Desktop QA]

Here is the pdf sample that I use to reproduce this bug: http://www.dbsparks.com/research/html/SNRN02.pdf,  plus a correction for the flag settings.