This change does the following:
* Address TODO to remove getEmptyContainer helper.
* Not set container bg-color. The old code is incorrect, causing it to
not have any effect. It sets color to an array (item.color) rather
css string. Also in most cases it would set it to black background
which is incorrect.
* only add border instructions when there is actually a border
* reduce memory consumption by not creating new 3 element arrays for
annotation colors. In fact according to spec, this would be incorrect,
as the default should be "transparent" for an empty array. Adobe
Reader interprets a missing color array as black however.
Note that only Link annotations were actually setting a border style and
color. While Text annotations might have calculated a border they did
not color it. This behaviour is now controlled by the boolean flag.
According to practical experiments, falling back to "Helvetica" when we encounter a non-embedded "[Century Gothic](http://en.wikipedia.org/wiki/Century_Gothic)" `CIDFontType2` font seems to work well.
(Also, the section on Wikipedia about "Printer ink usage" *might* provide some anecdotal evidence that Century Gothic is a fairly standard sans-serif font.)
Obviously this patch doesn't make "Century Gothic" fonts render perfectly, as is often the case with non-embedded fonts, but all the text is now legible in the referenced issues.
Fixes 4722.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=879561.
Fixes two issues:
- #4456 : The first 100 bytes are often not unique as they can be
filled with standard PDF headers - so we use the first 200 KB instead.
(This may be overkill)
- Some documents we encountered have invalid xref ids, which were
always coming out as ‘0000000000000000’ - so we detect that and use the
MD5 instead.
When submitting PR 5276 there wasn't a good PDF file to include in the test suite. However, with https://bugzilla.mozilla.org/show_bug.cgi?id=1108753, we now have a better source for a test file, hence this patch.
This is a tentative patch that adds *very* basic support for non-embedded Wingdings fonts (a Windows version of Dingbats), by falling back to the ZapfDingbats encoding. Obviously this approach will not work perfectly, but in my opinion it seems to work reasonably well in pratice.
Instead of this very simple patch, another option would be to try and include more complete glyph data for Wingdings, e.g. a Unicode map and glyph widths, similar to what was done for ZapfDingbats.
However there is, in my opinion, one important difference between Wingdings and ZapfDingbats: ZapfDingbats is part of the 14 standard fonts, which in previous versions of the PDF specification was assumed to be available in PDF readers. To improve compatibility with older files, it thus makes sense for us to include data for ZapfDingbats.
However Wingdings has never been a standard font in PDF files, hence PDF files using it *should* thus contain all the necessary font data.
Given the above, I thus believe that it should be OK to fall back to ZapfDingbats for now. If non-embedded Wingdings fonts turns out to be *a lot* more common, then we can revisit this later.
Fixes 4301 completely.
Fixes 4837 almost completely. With this patch the bullets are displayed correctly, but the arrows are not of the correct type.
Fixes `artofwar.pdf`, pages 14 and 15.
maskData comes out of maskCtx.getImageData, so is 0..255 clamped, and
the used multiplications will not create fractions needing rounding,
neither would addition.
