PR 4259 fixed a large number of font bugs, but none of those where added as test-cases. This was, in my opinion, unfortunate since it increases the risk of regressions in the future when other font bugs are fixed.
This PR simply adds a few more test-cases, to improve our test coverage somewhat.
document.documentElement.style is null in some XML documents.
The previous snippet caused the following error:
Uncaught TypeError: Cannot use 'in' operator to search for 'animation' in null
To fix this bug, `'animation' in document.documentElement.style` has been
replaced with `CSS.supports('animation', '9s')`. This method was introduced
in Chromium 28, but it is not necessary to detect whether this method is
supported because the required createShadowRoot method for embeds is not
available in Chromium 32 and earlier.
This change avoids the element stringification caused by for..in for the
vast majority of CMaps.
When loading the PDF from issue #4580, this change reduces peak RSS from ~650
to ~600 MiB, and improves overall speed by ~20%, from 902 ms to 713 ms. Other
CMap-heavy documents will also see improvements.
This lets the JS engine resize the array elements buffer immediately,
thus avoiding some intermediate resizings. This can save multiple MiBs
of reallocation in text-heavy files.
If a user downgrades from Chromium 35+ to 34, then the PDF Viewer
extension will not work any more because the extension assumes
that certain features were available based on the cached feature
detection results.
To resolve this problem, all feature detection scripts run again
if the browser was downgraded.
In b5b94a4af3, i.e. PR #4259, we stopped using cidmaps.js. Despite that, it's still included when PDF.js is built. At almost 0.5 MB (and approx. 7000 lines), this is currently the single largest file in the codebase.
Including such a large file in the builds, when it is not actually used, seems extremely wasteful; hence this patch.
The absence of this property caused the following error in PDFView.download:
Cannot read property 'split' of undefined
This property was unset when the PDF was loaded through a typed array instead
of a URL. With the fix, the file name will default to "document.pdf", as
defined by getPDFFileNameFromURL in web/ui_utils.js
I have a large PDF where this function is called 1.6 million times
during loading. Minimizing the string concatenations reduces the
cumulative allocations done by Firefox within this function from 113 MB
to 48 MB.
