Letter too bold

[automatedbugreportingfacility]

This is a regression from PR #4615. The letter "F" on page 6 is unreadable.

URL: http://chrishecker.com/images/3/33/Gdmogl.pdf
1.1.209: https://i.imgur.com/IobYdDE.png
0.8.990: https://i.imgur.com/s188qBb.png

fc1e248 is the first bad commit
commit fc1e248
Author: Jonas Jenwald
Date: Fri Apr 11 20:19:39 2014 +0200

Enforce minimum line widths

[timvandermeij]

/cc @Snuffleupagus

[Snuffleupagus]

In order to try avoiding drawing too thin, and thus nearly invisible, lines we use the getSinglePixelWidth method. Since this is a heavy operation, we attempt to cache the result (in cachedGetSinglePixelWidth) in order to try and speed up the rendering of PDF files with lots of drawing operations (e.g. maps).

We are currently invalidating that cache in some circumstances (currently on restore and transform), to avoid incorrect rendering. However, judging by this issue, it seems that we might simply not be invalidating the cache in every case that we actually should.

[timvandermeij]

@automatedbugreportingfacility Thanks again for the high quality bug reports! Usually we are able to fix mentioned regressions quickly because of that.

[automatedbugreportingfacility]

No problem, thank you for taking your time to fix these issues and keep pdf.js moving forward despite Mozilla pulling resources towards other projects.