SVG scaling by img directives has subtly changed; where before size=wxh
would preserve aspect ratio, this cannot be done when passing them through
and so specifying both a width and height can change the SVG's aspect
ratio.
(This patch looks significantly more complex than it was, because a large
block of code had to be indented.)
[smcv: drop trailing whitespace, fix some spelling]
This mitigates CVE-2016-3714. Wiki administrators who know that they
have prevented arbitrary code execution via other formats can re-enable
the other formats if desired.
A site administrator might unwisely set allowed_attachments to
something like '*.jpg or *.png'; if they do, an attacker could attach,
for example, a SVG file named attachment.jpg.
This mitigates CVE-2016-3714.
$im->Read() takes a filename-like argument with several sets of special
syntax. Most of the possible metacharacters are escaped by the
default `wiki_file_chars` (and in any case not particularly disruptive),
but the colon ":" is not.
It seems the way to force ImageMagick to treat colons within the
filename as literal is to prepend a colon, so do that.
in analogy to sparklines, this renders scaled imgs to
data:img/...;base64,... urls in preview mode.
if the image is already present on the server (eg because it was not
just inserted), the already rendered image is referenced instead.
there is now a size calculating part (which chooses a final size) and a
scaling part (which triggers if the sizes calculated by the former
indicate a downscaling).
this solves the issue of unproportional upscalings
(bugs/image_rescaling_distorts_with_small_pictures).
also, "small" pdf files (or pdf files without explicit size settings),
which would not be converted under the old mechanism, now get rendered
to pngs.
this commit affects a unit test: while svgs were previously
unconditionally rendered to pngs, this now only happens on downscaling.
this is intentional -- while a small version of an svg graphic is
likely to be more compact when rendered (eg as a preview), a large
version would not have that benefit, and why convert something that
browsers basically can show and be inconsistend with how other images
are handled. the new unit test simply makes the original svg larger to
check for the same behaviros as before.
this allows picking a page from a pdf. also, this enhances performance
greatly when rendering pdfs, as only the first page is rasterized.
(otherwise, imagemagick would treat the pdf as a list of images, work
with all of them, until finally only the first page gets saved). the
default parameter of 0 will select the single image contained in typical
image files anyway, so no specialcasing between single- and multifile
containers is needed.
imagemagick, when reading an image, sets its magick parameter to
indicate the file type, overriding the explicitly set file type for
output if it is set at creation.
as a result, previously (with graphicsmagick-libmagick-dev-compat
1.3.18-1 providing Image::Magick), svg output files were not png,
neither svg, but mvg (imagemagick vector graphics).
Imagemagick does not generate svg images very well, but it can convert
them to png quite well.
For browsers that don't yet support displaying svg, this also provides a
workaround; just scale the svg down to get a png. But the workaround is
partial, since scaling the image larger, or leaving it the same size will
cause the original svg to be displayed. Since browsers are actively
improving svg support, this is good enough for me.
This way users can use all the other alignment values when not including a
caption. Also, it will work without the standard style, and I don't have to
worry about regressions this way.
This is achieved by preparing CSS definitions that emulates the behavior
of the align attribute, and passing it to the outermost IMG wrapper
(A or TABLE) instead of passing the align value to IMG directly.
I had assumed that an image shown full size did not need add_depends, since
a change would not need a change to the displaying page.
But this is not true if the image is modified and its size changes. Then
the page needs to update its img tag to reflect the current size.
If an image was resized smaller, with width and height specified to values
that did not fit its aspect ratio, the image tag with/height were not
adjusted to the actual size imagemagick chooses.
This was broken by 03449610d6.
To fix it right, it unfortunatly needs to always read the src image now,
in order to determine if the image is being displayed larger, or resized
smaller. When resized smaller, it then always uses the size of the
thumbnail, while for larger it calculates the size.
(Only way to get rid of this sometimes extra image read would be to change
it to not allow displaying images larger.)
Although imagemagick handles even really large sizes sanely, using a page
file, doing so would just waste time and disk space, since the browser
can be told to resize it larger.
Previously, [[!img bar.jpg]] on foo, where foo/bar.jpg exists, would
get a dependency equivalent to "glob(bar.jpg)" (which might not match
anything), rather than the correct "glob(foo/bar.jpg)".
(cherry picked from commit 85b2ec49ecd12dd23e5c432933457a72744ce7cb)
This was impressively broken. add_depends was being called with params
backwards, and on parameter was set to the name of the generated
file, which isn't in the source.
Now updates to images will update the page that contains them, thus
updating them. This is unncessary for fullsize images, so skipped.
This is sorta an optimisation, and sorta a bug fix. In one
test case I have available, it can speed a page build up from 3
minutes to 3 seconds.
The root of the problem is that $links{$page} contains arrays of
links, rather than hashes of links. And when a link is found,
it is just pushed onto the array, without checking for dups.
Now, the array is emptied before scanning a page, so there
should not be a lot of opportunity for lots of duplicate links
to pile up in it. But, in some cases, they can, and if there
are hundreds of duplicate links in the array, then scanning it
for matching links, as match_link and some other code does,
becomes much more expensive than it needs to be.
Perhaps the real right fix would be to change the data structure
to a hash. But, the list of links is never accessed like that,
you always want to iterate through it.
I also looked at deduping the list in saveindex, but that does
a lot of unnecessary work, and doesn't completly solve the problem.
So, finally, I decided to add an add_link function that handles deduping,
and make ikiwiki-transition remove the old dup links.
if suitable alternate text is unknown, then it should not be given.
empty alt text is suitable mainly for purely decorative images.
(cherry picked from commit 3cd7f67f0cf894f4fd5ba16f68e82e4f7bdbfdc5)
I think this used to be a fatal error, not just inline error, so I don't
know why it was never noticed, but if a page that an img directive mentions
gets deleted, bestlink() returns a file that no longer exists, and
srcfile() throws an error.
Note that bestlink's behavior of returning a deleted file could be
considered buggy. But, if it's changed to not do that, the page with the img
on it is not updated at all when the file is removed.
Amitai Schlair
Simon McVittie
chrysn
Joey Hess
Per Carlson
Joey Hess
Giuseppe Bilotta
Simon McVittie
Gabriel McManus
Joey Hess