*Follow-up to PR 6299.*
This patch reduces unnecessary code duplication for the `canvas` to `image` conversion. It also does a bit of re-ordering (and adds new lines) in `_getPageDrawContext`, since that function currently is a bit hard to read.
Since some browsers render `null` characters, and others don't, this patch adds a way to remove them to prevent display issues in the viewer UI.
Given that documents may contain very long outlines, I've added a utility function to avoid creating a lot of unnecessary `RegExp` objects.
To avoid any future issues, this utility function is used for both the outline and the attachments.
Fixes 6416.
This patch adjusts `get fingerprint` to also check that the `/ID` entry contains (non-empty) strings, to prevent more possible failures when loading corrupt PDF files (follow-up to PR 5602).
Note that I've not actually encountered such a PDF file in the wild. However given that `stringToBytes` will assert that the input is a string, and that we'll thus fail to load a document unless `get fingerprint` succeeds, making this more robust seems like a good idea to me.
For (1, 0) cmaps, we have two different codepaths depending on whether the font has/hasn't got an encoding. But with (3, 1) cmaps we don't have a good fallback when the encoding is missing, hence this patch changes `readCmapTable` to only choose a (3, 1) cmap table if the font is non-symbolic *and* an encoding exists. Without this, we'll not be able to successfully create a working glyph map for some TrueType fonts with (3, 1) cmap tables.
Fixes 6410.
Prior to PR 6242, the width of all outline items was set such that their right (or left, in RTL locales) edges lined up vertically. In my opinion that looked more consistent, therefore this patch adjusts the CSS to make sure that this will be the case again.
The patch also makes the `border-radius` values of outline items a bit more consistent.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1200096.
The problematic font has a `format 2` cmap, which we've never supported properly. Prior to PR 2606, we were able to fallback to a working state, despite not having proper support for that cmap format.
Obviously the best/correct solution would be to implement actual support for more cmap formats[1]. However, I'm hoping that a simple patch will be OK for now, given that:
- `format 2` cmaps seem to be quite rare in practice, since this has been broken for 2.5 years before anyone noticed.
- Having a simple patch will make potential uplifts a lot easier.
[1] See the specification at https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6cmap.html
Re: PR 4731.
Since the URL points to the Internet Archive, I think that adding a linked test-case should be OK. (Also, it's difficult to create reduced, or even `unit`, tests that accurately captures the brokenness of real-world PDF files.)
*Please note:* Since this is a `load` test, `makeref`ing won't be needed.
Our current test coverage for vertical text is somewhat lacking, as evident from e.g. issue 6387. That regression could easily have been avoided if the `taro` test-case would have been an `eq` test, as well as an `text` test.
Currently we only attempt to test the *first* page, since `lastPage == 1`, but given that it's subsequently skipped we end up not testing anything.
*Note:* I've verified that the *second* page actually contains the kind of Colour space that the test was intended to check for.
It appears to me that the `expanded/collapsed` part of the names got switched around, since I'd expect the following convention:
- `v` == expanded
- `>` == collapsed
