pdftocairo -pdf adds adds characters
Submitted by Jason Crain
Assigned to Adrian Johnson @ajohnson
Link to original bug (#105579)
Description
Created attachment 138181 anonymized.pdf
I received a file from gour on the poppler IRC. With recent versions of cairo, printing with evince adds some characters to the document. I don't believe I'm allowed to share the original file so I'm attaching this anonymized version.
This is reproducible through poppler's pdftocairo program. Running pdftocairo -pdf anonymized.pdf bad.pdf produces a pdf that shows additional characters. I traced the regression to this commit:
commit 49536227 (refs/bisect/bad) Author: Adrian Johnson ajohnson@redneon.com Date: Sun Sep 27 08:27:53 2015 +0930
scaled-font-subsets: if glyph 0 used for rendering, remap to different index
Some broken pdfs use glyph 0 in embedded fonts for rendering instead of .notdef.
The cmap we use for embedding latin fonts does not allow rendering glyph 0. Ensure
if glyph 0 is used, it is mapped to a non 0 glyph in the subset.
[Bug 89082](https://bugs.freedesktop.org/show_bug.cgi?id=89082)This PDF includes a character mapped to glyph index 0. It's not supposed to be visible in the document, but after pdftocairo -pdf conversion it is.
Attachment 138181, "anonymized.pdf":
anonymized.pdf