Given that Internet Explorer is, since some time now, no longer supported in the PDF.js library this `<meta>` tag can also be removed (added in PR 6374).
When working on PR 13612, I mostly prioritized a simple solution that didn't require touching a lot of code. However, while working on PR 13735 I started to realize that the static `Name.empty` construction really wasn't a good idea.
In particular, having a special `Name`-instance where the `name`-property isn't actually a String is confusing (to put it mildly) and can easily lead to issues elsewhere. The only reason for not simply allowing the `name`-property to be an *empty* string, in PR 13612, was to avoid having to touch a lot of existing code. However, it turns out that this is only limited to a few methods in the `PartialEvaluator` and a few of the `BaseLocalCache`-implementations, all of which can be easily re-factored to handle *empty* `Name`-instances.
All-in-all, I think that this patch is even an *overall* improvement since we're now validating (what should always be) `Name`-data better in the `PartialEvaluator`.
This is what I ought to have done from the start, sorry about the code churn here!
Currently it's possible to run e.g. `gulp unittest`, `gulp fonttest`, and `gulp integrationtest` *separately* on the bots; see https://github.com/mozilla/botio-files-pdfjs
However, it's not possible to run *only* the `gulp browsertest` command on the bots without also running the full test-suite. In some cases, e.g. if the "browsertest" times out, having a way to only re-run those would thus save some time and resources.
If/when this patch lands, I'll follow-up with a patch adding a new `on_cmd_browsertest.js` file to the https://github.com/mozilla/botio-files-pdfjs repository.
*Please note:* This patch doesn't fix rendering of (various) patterns in browsers/environments without full `CanvasPattern.setTransform()` support, but it at least prevents outright failures and thus allows the rest of the page to render.
This patch provides a temporary work-around for Firefox 78 ESR[1], and for Node.js environments (see issue 13724), where rendering is currently completely broken.
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[1] Please note that the `createMatrix` helper function doesn't actually work as intended. The reason is that it's not `DOMMatrix` itself which is unsupported in older Firefox versions, but rather calling `CanvasPattern.setTransform(...)` with a `DOMMatrix`-argument.
Furthermore, the `createSVGMatrix` fallback won't actually help either since that method doesn't accept any parameters and would thus require *manually* specifying the matrix-state; see e.g. https://developer.mozilla.org/en-US/docs/Web/API/CanvasPattern/setTransform#examples
Finally, given that it's less than a month to the [Firefox 91 ESR release](https://wiki.mozilla.org/RapidRelease/Calendar) and that as-is all patterns are completely broken e.g. when using the latest viewer in Firefox 78 ESR, I'm just not convinced that it's worth the "hassle" of providing a more proper work-around.
This way we ensure that these BBox values are *always* defined as expected for every `case`-block, and we also don't need to duplicate the lookup in multiple places. (Also, the patch removes a couple of unnecessary line-breaks in existing comments.)
Fixes https://github.com/mozilla/pdf.js/pull/13691#pullrequestreview-702356627, which was flagged by LGTM.
- font line height is taken into account by acrobat when it isn't with masterpdfeditor: I extracted a font from a pdf, modified some ascent/descent properties thanks to ttx and the reinjected the font in the pdf: only Acrobat is taken it into account. So in this patch, line heights for some substituted fonts are added.
- it seems that Acrobat is using a line height of 1.2 when the line height in the font is not enough (it's the only way I found to fix correctly bug 1718741).
- don't use flex in wrapper container (which was causing an horizontal overflow in the above bug).
- consequently, the above fixes introduced a lot of small regressions, so in order to see real improvements on reftests, I fixed the regressions in this patch:
- replace margin by padding in some case where padding is a part of a container dimensions;
- remove some flex display: some containers are wrongly sized when rendered;
- set letter-spacing to 0.01px: it helps to be sure that text is not broken because of not enough width in Firefox.
