I just realized that none of our current unit-tests cover this particular part of the Page Label parsing code, hence this patch adjusts an existing test PDF to include a "St" entry in the Page Label dictionary.
*This patch fixes something that I noticed while debugging https://bugzilla.mozilla.org/show_bug.cgi?id=1308536.*
The PDF file contains a font called "NuptialScript", which unfortunately is not embedded. Since that is a non-standard font we will not be able to render it entirely correct. However, by adding "NuptialScript" to the `getNonStdFontMap`, we can at least improve the rendering slightly by using an italic (serif) fallback font.
This patch adds support for non-embedded Arial Black fonts, that use a `Arial-Black...` format for the font names.
Also, this patch changes `canvas.js` such that we always render Arial Black fonts with the maximum weight, which actually improves a number of existing test-cases. This should thus explain the test "failures", which are clear improvements compared with e.g. Adobe Reader.
Fixes 7835.
By only allowing very specific type of `JavaScript` actions, and also utilizing the existing `URL` validation, this patch shouldn't pose too much risk.
Fixes one of the points in issue 3897 (with the PDF file taken from issue 3438).
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=843699 (probably, since that bug doesn't contain a test-case).
It seems that certain bad PDF generators can create badly encoded "Prefix" entries for Page Labels, one example being http://ukjewishfilm.org/wp-content/uploads/2015/09/Jewish-Film-Festival-Programme-ONLINE.pdf.
Unfortunately I didn't come across such a PDF file while adding the API support for Page Labels, but with them now being used in the viewer I just found this issue. With this patch, we now display the Page Labels in the same way as Adobe Reader.
The original code is difficult to read and, more importantly, performs
actions that are not described in the specification. It replaces empty
names with a backtick and an index, but this behavior is not described
in the specification. While the specification is not entirely clear
about what should happen in this case, it does specify that the `T`
field is optional and that multiple field dictionaries may have the same
fully qualified name, so to achieve this it makes the most sense to
ignore missing `T` fields during construction of the field name. This is
the most specification-compliant solution and, judging by opened issue #6623, also the required and expected behavior.
In general we neither want, nor can, support arbitrary `Launch` actions. But in practice, all the cases we've seen so far just contains relative URLs to other PDF files. Building on PR 7689, we can thus at least support basic `Launch` actions.
Note that in `FIREFOX/MOZCENTRAL/CHROME` builds of the standard viewer the `docBaseUrl` parameter will be set by default, since in that case it makes sense to use the current URL as a base.
For the `GENERIC` viewer, or the API itself, it doesn't make sense to try and set the `docBaseUrl` by default. However, custom deployments/implementations may still find the parameter useful.
Note that this will automatically reject any relative URL.
To make the API more useful to consumers, URLs that are rejected will be available via the `unsafeUrl` property in the data object returned by `PDFPageProxy_getAnnotations`.
The patch also adds a bit more validation of the data for `Named` actions.
This not only reduces code duplication, but it also allow us to easily support the same kind of URLs we currently do for Link annotations in the Outline as well.
While the array argument to TJ should only contain strings and numbers, other
unfortunate items are found in PDFs in the wild, e.g.:
[(Grandes) 0.0 Tc
-250.0 (Client\350les,) 0.0 Tc
-250.0 (Financements) 0.0 Tc
-250.0 (et) 0.0 Tc
-250.0 (March\351s) ] TJ
getOperatorList already properly ignores any non-string, non-numeric values in
TJ arrays; without this patch to getTextContent, returned text items can have
NaN widths due to calculations being applied to those non-numeric values.
For PDF files with multiple `/Filter`s, where the `/Length` entry is zero, we fail to render the file correctly. The reason is that `maybeLength` is `null` for the every filter except the first, and `!maybeLength` is thus truthy.
Hence it seems that we should completely ignore the `/Length` entry and also explicitly check `maybeLength === 0`.
Note that I've not (yet) come across a PDF file with this issue in the wild, but given all the stupid things PDF generators do I wouldn't be surprised if such a file actually exists. In order to prevent a possible future bug, I'm submitting this patch which includes a hand-edited PDF file that we currently cannot render correctly (but e.g. Adobe Reader can).
Directly use the hexadecimal representation, just like the
`AnnotationFlags`, to avoid calculations and to improve readability.
This allows us to simplify the unit tests for text widget annotations as
well.
Unfortunately PR 7633 missed, and I didn't catch it during review, to update `test/driver.js` such that the `forms` tests takes the correct code-path.
This resultet in the `forms` reference test images looking better than they should, and more problematicly differing from the rendering in the viewer.
With this patch, the tests now correctly skip over any `Appearance` streams.
The `forms` tests now highlights quite clearly (e.g. look at `annotation-tx2.pdf`/`annotation-tx3.pdf`) that we cannot just skip the `Appearance` streams when rendering forms. Hence we're going to have to find a way to fix that *before* enabling forms by default, since both display *and* print would look completely wrong otherwise.
Finally, this patch also uncovers one more existing bug that still needs to be fixed, since the current `rasterizeAnnotationLayer` in `test/driver.js` isn't able to handle the contents of e.g. `<input>` and `<textarea>`.
This patch improves the unit tests by testing the support for read-only
and multiline fields. Moreover, we add a reference test to ensure that
the text widgets are not only rendered, but also that their contents are
styled properly.
Finally, we perform minor improvements in `src/core/annotation.js`, for
example adding missing comments.
For embedded Type1 fonts without included `ToUnicode`/`Encoding` data, attempt to improve text selection by using the `builtInEncoding` to amend the `toUnicode` map (issue 6901, issue 7182, issue 7217, bug 917796, bug 1242142)
Even though this patch passes all tests (unit/font/reference) locally, including the new ones that I added in PR 7621, I'm still a bit nervous about modifying the code that choose the fallback encoding for fonts without an `/Encoding` entry.
Note that over the years this code has been changed on a number of occasions, see a possibly incomplete [list here], to deal with various cases of incorrect font data.
According to the PDF specification, see http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/PDF32000_2008.pdf#G8.1904184, it seems that we should fallback to the `StandardEncoding` for Nonsymbolic fonts.
There's obviously a risk that fixing this particular issue *could* break other PDF files for which we don't have tests. However I've tried to change the logic as little as possible in this patch, to hopefully reduce possible breakage.
Based on debugging numerous font issue, it seems that a lot of fonts actually set the Symbolic flag, even when they are in fact *not* Symbolic. Fonts actually marked as Nonsymbolic seem to be somewhat less common, which I hope should reduce the risk of the patch somewhat.
Fixes 7580.
Note that in order to prevent any possible issues, this patch does *not* try to amend the `toUnicode` data for Type1 fonts that contain either `ToUnicode` or `Encoding` entries in the font dictionary.
Fixes, or at least improves, issues/bugs such as e.g. 6658, 6901, 7182, 7217, bug 917796, bug 1242142.
I've started to look into how we can fix issue 7580, but quickly became worried that fixing it could easily mean that we'd trade one fixed PDF file for a multitude of broken ones.
Hence I started going through the history of the code that choose the fallback encoding, and noticed that it has been changed a number of times over the years to deal with various cases of weirdness/errors in non-embedded fonts.
To my relief it turned out that almost all the PRs, please see a possibly incomplete [list here], that changed this code actually included `eq` test-cases.
However, in one case it appears that a PR missed to add a test-case. Furthermore since the fallback encoding may also be the only source for creating a `toUnicode` map, changing the encoding could possibly regress only the text-selection despite a PDF file still rendering correctly.
Therefore, this PR adds one new `eq` test, and also a number of additional `text` tests for PDF files already present in the test-suite.
Note that it's obviously possible that there's a certain overlap between the added tests, but I'd be *a whole lot* more concerned with causing regressions.
