*This patch basically extends the approach from PR 10392, by also checking the last page.*
Currently, in e.g. the `Catalog.numPages`-getter, we're simply assuming that if the /Pages-tree has an *integer* /Count entry it must also be correct/valid.
As can be seen in the referenced PDF documents, that entry may be completely bogus which causes general parsing to breaking down elsewhere in the worker-thread (and hanging the browser).
Rather than hoping that the /Count entry is correct, similar to all other data found in PDF documents, we obviously need to validate it. This turns out to be a little less straightforward than one would like, since the only way to do this (as far as I know) is to parse the *entire* /Pages-tree and essentially counting the pages.
To avoid doing that for all documents, this patch tries to take a short-cut by checking if the last page (based on the /Count entry) can be successfully fetched. If so, we assume that the /Count entry is correct and use it as-is, otherwise we'll iterate through (potentially) the *entire* /Pages-tree to determine the number of pages.
Unfortunately these changes will have a number of *somewhat* negative side-effects, please see a possibly incomplete list below, however I cannot see a better way to address this bug.
- This will slow down initial loading/rendering of all documents, at least by some amount, since we now need to fetch/parse more of the /Pages-tree in order to be able to access the *last* page of the PDF documents.
- For poorly generated PDF documents, where the entire /Pages-tree only has *one* level, we'll unfortunately need to fetch/parse the *entire* /Pages-tree to get to the last page. While there's a cache to help reduce repeated data lookups, this will affect initial loading/rendering of *some* long PDF documents,
- This will affect the `disableAutoFetch = true` mode negatively, since we now need to fetch/parse more data during document initialization. While the `disableAutoFetch = true` mode should still be helpful in larger/longer PDF documents, for smaller ones the effect/usefulness may unfortunately be lost.
As one *small* additional bonus, we should now also be able to support opening PDF documents where the /Pages-tree /Count entry is completely invalid (e.g. contains a non-integer value).
Fixes two of the issues listed in issue 14303, namely the `poppler-67295-0.pdf` and `poppler-85140-0.pdf` documents.
Given that not all pages necessarily are being accessed, or that the pages may be accessed out of order, using a `Map` seems like a more appropriate data-structure here.
Furthermore, this patch also adds (currently missing) caching for XFA-documents. Loading a couple of such documents in the viewer, with logging added, shows that we're currently re-creating `Page`-instances unnecessarily for XFA-documents.
For this particular PDF document, we have `/W [1 2 166666666666666666666666666]` which obviously makes no sense.
While this patch makes no attempt at actually validating the entries in the /W-array, we'll now simply abort all processing when the end of the PDF document has been reached (thus preventing hanging the browser).
Please note that this patch doesn't enable the PDF document to be loaded/rendered, but at least it fails "correctly" now.
Fixes one of the issues listed in issue 14303, namely the `REDHAT-1531897-0.pdf`document.
This bug was surprisingly difficult to track down, since it didn't just depend on range-requests being used but also on how quickly the document was loaded. To even be able to reproduce this locally, I had to use a very small `rangeChunkSize`-value (note the unit-test).
The cause of this bug is a bogus entry in the XRef-table, causing us to attempt to request data from *beyond* the actual document size and thus getting into an infinite loop.
Fixes *one* of the issues listed in issue 14303, namely the `PDFBOX-4352-0.pdf` document.
*Please note:* These changes will primarily benefit longer documents, somewhat at the expense of e.g. one-page documents.
The existing `PDFDocumentProxy.getStats` function, which in the default viewer is called for each rendered page, requires a round-trip to the worker-thread in order to obtain the current document stats. In the default viewer, we currently make one such API-call for *every rendered* page.
This patch proposes replacing that method with a *synchronous* `PDFDocumentProxy.stats` getter instead, combined with re-factoring the worker-thread code by adding a `DocStats`-class to track Stream/Font-types and *only send* them to the main-thread *the first time* that a type is encountered.
Note that in practice most PDF documents only use a fairly limited number of Stream/Font-types, which means that in longer documents most of the `PDFDocumentProxy.getStats`-calls will return the same data.[1]
This re-factoring will obviously benefit longer document the most[2], and could actually be seen as a regression for one-page documents, since in practice there'll usually be a couple of "DocStats" messages sent during the parsing of the first page. However, if the user zooms/rotates the document (which causes re-rendering), note that even a one-page document would start to benefit from these changes.
Another benefit of having the data available/cached in the API is that unless the document stats change during parsing, repeated `PDFDocumentProxy.stats`-calls will return *the same identical* object.
This is something that we can easily take advantage of in the default viewer, by now *only* reporting "documentStats" telemetry[3] when the data actually have changed rather than once per rendered page (again beneficial in longer documents).
---
[1] Furthermore, the maximium number of `StreamType`/`FontType` are `10` respectively `12`, which means that regardless of the complexity and page count in a PDF document there'll never be more than twenty-two "DocStats" messages sent; see 41ac3f0c07/src/shared/util.js (L206-L232)
[2] One example is the `pdf.pdf` document in the test-suite, where rendering all of its 1310 pages only result in a total of seven "DocStats" messages being sent from the worker-thread.
[3] Reporting telemetry, in Firefox, includes using `JSON.stringify` on the data and then sending an event to the `PdfStreamConverter.jsm`-code.
In that code the event is handled and `JSON.parse` is used to retrieve the data, and in the "documentStats"-case we'll then iterate through the data to avoid double-reporting telemetry; see https://searchfox.org/mozilla-central/rev/8f4c180b87e52f3345ef8a3432d6e54bd1eb18dc/toolkit/components/pdfjs/content/PdfStreamConverter.jsm#515-549
Given that all modern browsers now support `postMessage` transfers, and have for years, it no longer seems necessary for the PDF.js library to support using Workers unless the `postMessage` transfers functionality is available.
This patch is a follow-up to PR 11123, which made it impossible to *manually* disable `postMessage` transfers for performance reasons (since it increases memory usage), which hasn't caused any bug reports as far as I know.[1]
Hence we'll now only support *proper* Worker implementations, with fully working `postMessage` transfers, and fallback to using "fake" Workers otherwise.
---
[1] At the time of that PR we still "supported" IE, which is why this code was left intact.
There's obviously no guarantee that this will work in general, if the document is sufficiently corrupt, but it should hopefully be better than just throwing `InvalidPDFException` as currently happens.
Please note that, as is often the case with corrupt documents, it's somewhat difficult to know if we're rendering the document "correctly" with this patch[1]. In this case even Adobe Reader cannot open the document, which is always a good sign that it's *really* corrupt, however we're at least able to render *something* with this patch.
---
[1] Whatever "correct" even means when dealing with corrupt PDF documents, where often times different PDF viewers won't agree completely.
- it aims to fix https://bugzilla.mozilla.org/show_bug.cgi?id=931481;
- real space chars are pushed in the chunk but when there is an extra spacing, the next char position must be compared with the previous one;
- for example, an extra spacing can cancel a space so visually there are no space.
- First step to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1737260;
- several interactive pdfs use the possibility to hide/show buttons to show different icons;
- render pushbuttons on their own canvas and then insert it the annotation_layer;
- update test/driver.js in order to convert canvases for pushbuttons into images.
In `beginGroup` we create a new canvas that is the size of the
bounding box and we translate it to the offset. This means we don't need to
also apply the bounding box during `paintFormXObjectBegin`.
This improves #6961 quite a bit, but it still is missing the indention
in the ruler.
- it aims to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1739502;
- when the target area was the current content area, everything was pushed in it instead of creating a new one (and consequently a new pageArea is created).
- the pdf shows an alignment issue on page 4:
- the hAlign is "center" but the subform was the width of its parent, so compute the real width of the subform with tb layout;
- there is an extra empty page at the end of the pdf:
- there is a subform with some hidden elements which are not rendered for now (since there is no plugged JS engine it isn't possible to draw them in changing their visibility).
- so in case a subform is empty and has no real dimensions (at least one is 0), we just consider it as empty.
Subfrom nomin displays even though it's subform is set to <occur max=-1 min=0>
If we look through specs of XFA 3.3 : https://www.pdfa.org/norm-refs/XFA-3_3.pdf
- The min attribute is used when processing a form that contains data. Regardless of the data at least this number of instances is included. It is permissible to set this value to zero, in which case the container is entirely excluded if there is no data for it.
However, in our case it doesn't happen, because we let our empty dataNode get through. Though by setting a clause:
- eliminate unmatched data with occur min=0
we are checking our empty data and sending it to uselessNode array where at the end it gets removed;
Very short strings can narrowly miss the existing Bidi-detection threshold, leading to incorrect text-selection and copying behaviour.
In my testing, neither Adobe Reader or PDFium seem to handle copying "correctly" for this document. Hence it's not entirely clear to me that we actually want to fix this, since tweaking these heuristics can *obviously* cause regressions elsewhere (and our test coverage for RTL-text isn't exactly great).
Trying to render these Annotation-types, when the borderWidth is `0`, causes a "hairline" border to appear. If these Annotations included an appearance stream, as they are supposed to, this wouldn't have happened and the simplest solution here seem to be to just ignore these particular Annotations.
- PR #13257 fixed a lot of issues but not all and this patch aims to fix almost all remaining issues.
- the idea in this new patch is to compare position of new glyph with the last position where a glyph has been drawn;
- no space are "drawn": it just moves the cursor but they aren't added in the chunk;
- so this way a space followed by a cursor move can be treated as only one space: it helps to merge all spaces into one.
- to make difference between real spaces and tracking ones, we used a factor of the space width (from the font)
- it was a pretty good idea in general but it fails with some fonts where space was too big:
- in Poppler, they're using a factor of the font size: this is an excellent idea (<= 0.1 * fontSize implies tracking space).
*Please note:* This is a tentative patch, since I don't have the necessary a11y-software to actually test it.
To avoid having to add a new API-method just for a single string, I figured that adding the new property to the existing `documentInfo`-data (accessed via `PDFDocumentProxy.getMetadata` in the API) will hopefully be deemed acceptable.
In these cases there's no good reason, in my opinion, to duplicate the `shadow`-lines since that unnecessarily increases the risk of simple typos (see the previous patch).
With this typo the shadowing doesn't actually work, which causes these checks to be unnecessarily repeated. In this particular case it didn't have a significant performance impact, however we should definately fix this nonetheless.
If a PDF included an embedded TrueType font whose preferred character
map (cmap) was in "format 2", the code would select that character map
and then refuse to read it because of an unsupported format, thus
causing the characters not to be rendered. This commit implements
support for format 2 as described at the link below.
https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6cmap.html
This is unfortunately *yet another* bug in the `preEvaluateFont`-implementation, and I've lost count of the number of times I've had to tweak this code over the years :-(
I really cannot help thinking that PR 4423 was way too simplistic, since it missed a bunch of cases that leads to broken font rendering in many PDF documents.
Fixes https://bugzilla.mozilla.org/show_bug.cgi?id=1734802
- the exact sentence from the spec:
"The token SOLIDUS (a slash followed by no regular characters) introduces a unique valid name defined by the empty sequence of characters."
- so just remove the warning.
Note how both the annotationLayer and the document outline will apply various URL-related options when creating the link-elements.
For consistency the `xfaLayer`-rendering should obviously use the same options, to ensure that the existing options are indeed applied to all URLs regardless of where they originate.
- it aims to fix#12721.
- Thanks to PR #14023, we've now the fieldObjects in the annotation layer so we can easily map fields names on their id if needed.
- Reset values in the storage, in the JS sandbox and in the visible html elements.
In the referenced bug, the embedded fonts contain custom CMap-data that only include strings. Note how for embedded composite TrueType fonts we're using the CMap-data when building the glyph mapping, and currently we end up with a completely empty map because the code expects only CID *numbers*.
Furthermore, just fixing the glyph mapping alone isn't sufficient to fully address the bug, since we also need to consider this "special" kind of CMap-data when looking up glyph widths.
Having recently worked with, and reviewed patches touching, this code it seemed that it's probably not a bad idea to move that functionality into `createValidAbsoluteUrl` as new options instead.
For the `addDefaultProtocolToUrl` functionality in particular, the existing helper function was not only moved but slightly improved as well. Looking at the code, I realized that there's a small risk that it would incorrectly match a *relative* URL-string too.
With these changes, the `createValidAbsoluteUrl` call-sites in the `src/core/`-code can be simplified a little bit.
*Please note:* This patch may, indirectly, change the format of the `unsafeUrl`-property returned with relevant Annotations and OutlineItems; hence the `api-minor` tag.
However, I'd argue that it's actually more correct this way since the whole purpose of `unsafeUrl` is/was to return the URL data as-is without any parsing done.
- it aims to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1716758;
- some buttons have a JS action with the pattern `app.launchURL(...)` (or similar) so extract when it's possible the url and generate a <a> element with the href equals to the found url;
- pdf.js already had some code to handle that so this patch slightly refactor that.
- it aims to fix#14021;
- the N dict is empty here so just create a default one;
- it implies that the checked checkbox has no appearance so create a default one too in order to print it;
- in the pdf in the issue, a checked box is not printed because it has no default appearance so we need to guess its appearance from its state.
In order to implement this, we utilize the existing `bidi` function to infer the text-direction of /T and /Contents entries. While this may not be perfect in cases where one PopupAnnotation mixes LTR and RTL languages, it should work well enough in most cases.
To avoid having to add *two new* properties in lots of annotations, supplementing the existing `title`/`contents`-properties, this patch instead re-factors the existing code such that the properties are replaced by Objects (containing `str` and `dir`).
*Please note:* In order avoid breaking existing third-party implementations, `GENERIC`-builds of the PDF.js library will still provide the old `title`/`contents`-properties on annotations returned by `PDFPageProxy.getAnnotations`.
- In the pdf in issue #14071, some select fields don't contain any values;
- the corresponding node has a bindItems and a bind elements and _bindItems function was just not called.
*This is similar to the "isSymbolicFont"-property, which is no longer exported by default after PR 11777.*
Both "isMonospace" and "isSerifFont" are internal properties, used during font parsing and building of the glyph mapping on the worker-thread.
However both of these properties are completely unused on the main-thread and/or in the API, and accessing them they will now require setting the `fontExtraProperties`-option when calling `getDocument`.
With this patch we'll ensure that only valid absolute URLs can be used in XFA documents, similar to the existing validation done for "regular" PDF documents.
Furthermore, we'll also attempt to add a default protocol (i.e. `http`) to URLs beginning with "www." in XFA documents as well; this on its own is enough to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1731240
Currently we only exclude /Encoding entries that also contains a /Differences array, which is the cause of the text-selection problem in the referenced issue.
In order to address this we'll now also exclude /Encoding entries that contain one of the predefined *named* encodings, and no longer require that it also contains a /Differences array.
*Please note:* This patch cases a small "regression" in the `bug1130815-text` test-case, however this is actually an improvement when compared with Adobe Reader and PDFium (in Google Chrome).
This reduces some unnecessary duplication, since we currently have essentially the same code in a handful of places in the `Font.fallbackToSystemFont`-method.
In this particular case the `CMap`-data that we create contains only numbers, but no strings, which causes `PartialEvaluator.readToUnicode` to create a ToUnicode-map with only empty strings.
*Please note:* This is yet another case where I don't know if it's necessarily the best and most correct solution, but it does fix the referenced issue.
- it aims to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1722036.
- AS and V should share the same value for checkbox: it's at least what the specs say;
- the pdf in the above bug opens correctly in Acrobat so it likely means that AS is chosen over V.
*Please note:* All of this feels very handwavy, but at least it passes all tests locally. Hopefully we have enough tests for this part of the font code.
For non-embedded composite standard fonts with an "incomplete" /CIDToGIDMap, we'll now fallback to an *explicitly defined* /ToUnicode map even when that one happens to be an /Identity-H or /Identity-V map.
The `Font.fallbackToSystemFont` method is unfortunately getting more and more special-cases, however that might be unavoidable given all the weird non-embedded fonts found in the wild :-(
*This fixes something that I noticed, having recently looked at both the `Lexer.getObj` and `writeValue` code.*
Please note that I unfortunately don't have an example of a form where saving fails without this patch. However, given its overall simplicity and that unit-tests are added, it's hopefully deemed useful to fix this potential issue pro-actively rather than waiting for a bug report.
At this point one might, and rightly so, wonder if there's actually any real-world PDF documents where a `null` value is being used?
Unfortunately the answer is *yes*, and we have a couple of examples in the test-suite (although none of those are related to forms); please see: `issue1015`, `issue2642`, `issue10402`, `issue12823`, `issue13823`, and `pr12564`.
While some of the output looks worse to my eye, this behavior more
closely matches what I see when I open the PDFs in Adobe acrobat.
Fixes: #4706, #9713, #8245, #1344
The `MessageHandler`-implementation already handles either of these callbacks being undefined, hence there's no particular reason (as far as I can tell) to add no-op functions here.
Also, in a couple of `MessageHandler`-methods, utilize an already existing local variable more.
Following the STR in the issue, this patch reduces the number of `PartialEvaluator.getTextContent`-related `postMessage`-calls by approximately 78 percent.[1]
Note that by enforcing a relatively low value when batching text chunks, we should thus improve worst-case scenarios while not negatively affect all `textLayer` building.
While working on these changes I noticed, thanks to our unit-tests, that the implementation of the `appendEOL` function unfortunately means that the number and content of the textItems could actually be affected by the particular chunking used.
That seems *extremely* unfortunate, since in practice this means that the particular chunking used is thus observable through the API. Obviously that should be a completely internal implementation detail, which is why this patch also modifies `appendEOL` to mitigate that.[2]
Given that this patch adds a *minimum* batch size in `enqueueChunk`, there's obviously nothing preventing it from becoming a lot larger then the limit (depending e.g. on the PDF structure and the CPU load/speed).
While sending more text chunks at once isn't an issue in itself, it could become problematic at the main-thread during `textLayer` building. Note how both the `PartialEvaluator` and `CanvasGraphics` implementations utilize `Date.now()`-checks, to prevent long-running parsing/rendering from "hanging" the respective thread. In the `textLayer` building we don't utilize such a construction[3], and streaming of textContent is thus essentially acting as a *simple* stand-in for that functionality.
Hence why we want to avoid choosing a too large minimum batch size, since that could thus indirectly affect main-thread performance negatively.
---
[1] While it'd be possible to go even lower, that'd likely require more invasive re-factoring/changes to the `PartialEvaluator.getTextContent`-code to ensure that the batches don't become too large.
[2] This should also, as far as I can tell, explain some of the regressions observed in the "enhance" text-selection tests back in PR 13257.
Looking closer at the `appendEOL` function it should potentially be changed even more, however that should probably not be done here.
[3] I'd really like to avoid implementing something like that for the `textLayer` building as well, given that it'd require adding a fair bit of complexity.
In the PDF document some of the glyphs have bogus `differences`-entries[1] that cannot be resolved to valid glyph names, thus causing the glyph mapping to fail.
My initial idea was to use a similar approach as in the `PartialEvaluator._simpleFontToUnicode`-method, to extract the charCodes from those entries, however it turned out that that didn't actually help in this case (the mapping was still wrong).
To fix this I'm thus proposing that we fallback to the /ToUnicode map when no other useable data exists (e.g. no post-table), since it *hopefully* shouldn't make things any worse than leaving parts of the glyph map empty (which currently happens).
---
[1] As can be seem below, some of the entries are completely normal while others are non-standard:
```
Differences (array)
0 = 65
1 = /g5167
2 = /space
3 = /g11927
4 = /g17737
5 = /g11540
6 = /g2180
7 = /K
8 = /P
9 = /two
10 = /zero
11 = /one
12 = /five
13 = /four
14 = /g6932
15 = /g7246
16 = /g1691
17 = /g2343
18 = /g14792
19 = /g3325
20 = /g4280
21 = /g20383
22 = /g18166
23 = /g16988
24 = /g17943
25 = /g19223
26 = /g10830
27 = 97
28 = /g982
29 = /g1226
30 = /g5059
31 = /g2677
32 = /g1042
33 = /g11568
34 = /L
35 = /three
36 = /seven
37 = /g2364
38 = /g12063
39 = /g5356
40 = /g2173
41 = /g17877
42 = /g7273
43 = /g7647
44 = /g7224
45 = /g19327
46 = /g5054
47 = /g2342
48 = /g10136
49 = /g6856
50 = /g13381
51 = /g7257
52 = /g12093
53 = /g2359
```
- aims to fix https://bugzilla.mozilla.org/show_bug.cgi?id=1720179
- in some pdfs the XFA array in AcroForm dictionary doesn't contain an entry for 'datasets' (which contains saved data), so basically this patch allows to overwrite the AcroForm dictionary with an updated XFA array when doing an incremental update.
- when some named nodes in the template don't have their counterpart in datasets we create some nodes: the main node mustn't belong to the datasets namespace because it doesn't make sense and Acrobat Reader isn't able to read pdf with such nodes.
- so created nodes under a datasets node have a namespaceId set to -1 and consequently when serialized no namespace prefix will appear.
There's a fair number of regular expressions througout the code-base which are slightly more verbose than strictly necessary, in particular:
- We have a lot of regular expressions that use `[0-9]` explicitly, and those can be simplified to use `\d` instead.
- We have one instance of a regular expression containing a `A-Za-z0-9_` sequence, which can be simplified to use `\w` instead.
Despite its name, the fonts in ItcSymbol-family are "regular" fonts and not Symbol ones. However, given that the font name contains the word "Symbol" we ended up picking the wrong code-path in the `Font.fallbackToSystemFont`-method.
*Please note:* While this patch ensures that the text becomes readable, by falling back a standard font, the rendering will obviously not be perfect. However, that's the PDF generators "fault" since non-embedded fonts cannot be guaranteed to render correctly in all environments.
Testing:
- delete the pdf file while the initial request is inflight
- delete the pdf file after the initial request has finished
Repeat for a small file and large file, exercising both one-off and
chunked transports.
Something that I *just* realized is that while PR 13854 fixed an issue as reported, it could still cause bugs in other similarily broken documents since we'll not insert a matching endMarkedContent-operator in the operatorList.
Currently, in the `PartialEvaluator`, we only support Optional Content in Form-/XObjects. Hence this patch adds support for Image-/XObjects as well, which looks like a simple oversight in PR 12095 since the canvas-implementation already contains the necessary code to support this.
*This is a follow-up to PRs 13867 and 13899.*
This patch is tagged `api-minor` for the following reasons:
- It replaces the `renderInteractiveForms`/`includeAnnotationStorage`-options, in the `PDFPageProxy.render`-method, with the single `annotationMode`-option that controls which annotations are being rendered and how. Note that the old options were mutually exclusive, and setting both to `true` would result in undefined behaviour.
- For improved consistency in the API, the `annotationMode`-option will also work together with the `PDFPageProxy.getOperatorList`-method.
- It's now also possible to disable *all* annotation rendering in both the API and the Viewer, since the other changes meant that this could now be supported with a single added line on the worker-thread[1]; fixes 7282.
---
[1] Please note that in order to simplify the overall implementation, we'll purposely only support disabling of *all* annotations and that the option is being shared between the API and the Viewer. For any more "specialized" use-cases, where e.g. only some annotation-types are being rendered and/or the API and Viewer render different sets of annotations, that'll have to be handled in third-party implementations/forks of the PDF.js code-base.
This way there cannot be any *incorrect* cache hits, since Refs are guaranteed to be unique.
Please note that the reason for caching by Ref rather than doing something along the lines of the `localShadingPatternCache` (which uses a `Map` directly), is that TilingPatterns are streams and those cannot be cached on the `XRef`-instance (this way we avoid unnecessary parsing).
*This patch is very similar to the recently fixed `renderInteractiveForms`-options, see PR 13867.*
As far as I can tell, this *subtle* bug has existed ever since `AnnotationStorage`-support was first added in PR 12106 (a little over a year ago).
The value of the `includeAnnotationStorage`-option, as passed to the `PDFPageProxy.render` method, will (potentially) affect the size/content of the operatorList that's returned from the worker (for documents with forms).
Given that operatorLists will generally, unless they contain huge images, be cached in the API, repeated `PDFPageProxy.render` calls where the form-data has been changed by the user in between, can thus *wrongly* return a cached operatorList.
In the viewer we're only using the `includeAnnotationStorage`-option when printing, which is probably why this has gone unnoticed for so long. Note that we, for performance reasons, don't cache printing-operatorLists in the API.
However, there's nothing stopping an API-user from using the `includeAnnotationStorage`-option during "normal" rendering, which could thus result in *subtle* (and difficult to understand) rendering bugs.
In order to handle this, we need to know if the `AnnotationStorage`-instance has been updated since the last `PDFPageProxy.render` call. The most "correct" solution would obviously be to create a hash of the `AnnotationStorage` contents, however that would require adding a bunch of code, complexity, and runtime overhead.
Given that operatorList caching in the API doesn't have to be perfect[1], but only have to avoid *false* cache-hits, we can simplify things significantly be only keeping track of the last time that the `AnnotationStorage`-data was modified.
*Please note:* While working on this patch, I also noticed that the `renderInteractiveForms`- and `includeAnnotationStorage`-options in the `PDFPageProxy.render` method are mutually exclusive.[2]
Given that the various Annotation-related options in `PDFPageProxy.render` have been added at different times, this has unfortunately led to the current "messy" situation.[3]
---
[1] Note how we're already not caching operatorLists for pages with *huge* images, in order to save memory, hence there's no guarantee that operatorLists will always be cached.
[2] Setting both to `true` will result in undefined behaviour, since trying to insert `AnnotationStorage`-values into fields that are being excluded from the operatorList-building will obviously not work, which isn't at all clear from the documentation.
[3] My intention is to try and fix this in a follow-up PR, and I've got a WIP patch locally, however it will result in a number of API-observable changes.
By not adding any additional non-`Dict` entries to the list of candidates for merging of sub-dictionaries, we can very slightly reduce the amount of parsing required by not having to *again* iterate through unmergeable data.
Once we're finally able to get rid of SystemJS, which is unfortunately still blocked on [bug 1247687](https://bugzilla.mozilla.org/show_bug.cgi?id=1247687), we might also want to clean-up (or even completely remove) the `BaseException` abstraction and simply extend `Error` directly instead.
At that point we'd need to (explicitly) set the `name` on each class anyway, so this patch is essentially preparing for future clean-up. Furthermore, after the `BaseException` abstraction was added there's been *multiple* issues filed about third-party minification breaking our code since `this.constructor.name` is not guaranteed to always do what you intended.
While hard-coding the strings indeed feels quite unfortunate, it's likely the "best" solution to avoid the problem described above.
The value of the `renderInteractiveForms` parameter, as passed to the `PDFPageProxy.render` method, will (potentially) affect the size/content of the operatorList that's returned from the worker (for documents with forms).
Given that operatorLists will generally, unless they contain huge images, be cached in the API, repeated `PDFPageProxy.render` calls that *only* change the `renderInteractiveForms` parameter can thus return an incorrect operatorList.
As far as I can tell, this *subtle* bug has existed ever since `renderInteractiveForms`-support was first added in PR 7633 (which is almost five years ago).
With the previous patch, fixing this is now really simple by "encoding" the `renderInteractiveForms` parameter in the *internal* renderingIntent handling.
With the changes made in PR 13746 the *internal* renderingIntent handling became somewhat "messy", since we're now having to do string-matching in various spots in order to handle the "oplist"-intent correctly.
Hence this patch, which implements the idea from PR 13746 to convert the `intent`-strings, used in various API-methods, into an *internal* renderingIntent that's implemented using a bit-field instead. *Please note:* This part of the patch, in itself, does *not* change the public API (but see below).
This patch is tagged `api-minor` for the following reasons:
1. It changes the *default* value for the `intent` parameter, in the `PDFPageProxy.getAnnotations` method, to "display" in order to be consistent across the API.
2. In order to get *all* annotations, with the `PDFPageProxy.getAnnotations` method, you now need to explicitly set "any" as the `intent` parameter.
3. The `PDFPageProxy.getOperatorList` method will now also support the new "any" intent, to allow accessing the operatorList of all annotations (limited to those types that have one).
4. Finally, for consistency across the API, the `PDFPageProxy.render` method also support the new "any" intent (although I'm not sure how useful that'll be).
Points 1 and 2 above are the significant, and thus breaking, changes in *default* behaviour here. However, unfortunately I cannot see a good way to improve the overall API while also keeping `PDFPageProxy.getAnnotations` unchanged.
Given how trivial the `isEOF` function is, we can simply inline the check at the various call-sites and remove the function (which ought to be ever so slightly more efficient as well).
Furthermore, this patch also changes the `EOF` primitive itself to a `Symbol` instead of an Object since that has the nice benefit of making it unclonable (thus preventing *accidentally* trying to send `EOF` from the worker-thread).
Given that the GitHub Advanced Security workflow now covers everything that LGTM does, but generally faster and with better GitHub-integration, there's no longer much point in also running LGTM separately.
As a follow-up to this patch, we should also disable/remove the LGTM-integration from the PDF.js repository.
The PDF in bug 1721949 uses many unique pattern objects
that references the same shading many times. This caused
a new canvas pattern to be created and cached many times
driving up memory use.
To fix, I've changed the cache in the worker to key off the
shading object and instead send the shading and matrix
separately. While that worked well to fix the above bug,
there could be PDFs that use many shading that could
cause memory issues, so I've also added a LRU cache
on the main thread for canvas patterns. This should prevent
memory use from getting too high.
- All the scale factors in for the substitution font were wrong because of different glyph positions between Liberation and the other ones:
- regenerate all the factors
- Text may have polish chars for example and in this case the glyph widths were wrong:
- treat substitution font as a composite one
- add a map glyphIndex to unicode for Liberation in order to generate width array for cid font
- In order to better compute text fields size, use line height with no gaps (and consequently guessed height for text are slightly better in general).
- Fix default background color in fields.
- an Image element was created, attached to its parent but the $globalData property was not set and that led to an error.
- the pdf in bug 1722029 has 27 rendered rows (checked in Acrobat) when only one was displayed: this patch some binding issues around the occur element.
This patch makes use of the existing `ignoreErrors` option, thus allowing a page to continue parsing/rendering even if (some of) its sub-streams are corrupt. Obviously this may cause *part* of a page to be broken/missing, however it should be better than (potentially) rendering nothing.
Also, to the best of my knowledge, this is the first bug of its kind that we've encountered.
To avoid having to pass in a bunch of, for a `BaseStream`-instance, mostly unrelated parameters when initializing a `StreamsSequenceStream`-instance, I settled on utilizing a callback function instead to allow conditional Error-suppression.
Note that the `StreamsSequenceStream`-class is a *special* stream-implementation that we only use when the `/Contents`-entry, in the `/Page`-dictionary, consists of an Array with streams.
Apparently I didn't put one of the disable comments on the *correct* line, since I didn't read the instructions carefully enough, so let's try again.
Note that, most unfortunately, disabling of warnings isn't applied until *after* a patch has been merged.
Most of the warnings we don't really care about, and those are simply white-listed using inline comments; however two cases prompted actual code changes:
- In `src/display/pattern_helper.js` the branch in question is indeed unreachable, and should thus be safe to remove. (This code originated in PR 4192, which is now over seven years ago.)
- In `test/test.js`, the function in question indeed doesn't accept any arguments. (The patch also re-formats a string just above, which didn't seem worthy of a separated patch.)
This now leaves only *one* warning in the LGTM report, however that one is a false positive that we'll need to report upstream.
In cases where even the very *first* attempt at reading from an object will throw, simply ignoring such objects will help improve rendering of *some* corrupt documents.
Note that this will lead to more parsing in some cases, but considering that this only applies to *corrupt* documents that shouldn't be a big deal.
Bug 1721218 has a shading pattern that was used thousands of times.
To improve performance of this PDF:
- add a cache for patterns in the evaluator and only send the IR form once
to the main thread (this also makes caching in canvas easier)
- cache the created canvas radial/axial patterns
- for shading fill radial/axial use the pattern directly instead of creating temporary
canvas
Currently the `!mergeSubDicts` code-path is essentially just duplicated code, which we can easily avoid by simply moving that check. (This may lead to ever so slightly more parsing for this case, but the difference ought to be negligible in practice.)
- in real life some xfa contains xml like <xfa:data><xfa:Foo><xfa:Bar>...</xfa:data>
since there are no Foo or Bar in the xfa namespace the JS representation are empty
and that leads to errors.
- so the idea is to make all nodes under xfa:data namespace agnostic which means
that ns are removed from nodes in the parser but only xfa:data descendants.
*Please note:* The PDF document in issue 13751 is *dynamically* created (in e.g. Adobe Reader), with pages added when certain buttons are clicked, hence this patch simply fixes the breaking error and nothing more.
It looks like the current code contains a little bit too much copy-and-paste from the *similar* `index` branch above, since we cannot set the `startIndex` to a negative value. Note how it's being used to initialize the loop-variable, which is then used to lookup values in an Array and accessing the `-1`th element of an Array obviously makes no sense.
*This is yet another case where I've got no idea if the patch is correct, but it does at least fix a breaking error :-)*
Note how in the [`Binder._bindValue` method](683ce66a48/src/core/xfa/bind.js (L92-L93)), we're assuming that if a `data`-value exists then it'll also be possible to actually access it. For the `XFAAttribute`-implementation however, the second method is missing and that's what causes the breaking errors in issue 13748.
Please note that another possible way of "fixing" the error wouldn't been to simply change the exists-check to return `false`, and I could see that being a preferred solution.
However, the reason for submitting the current patch is that we get *fewer* warnings about Nodes with mis-matched types this way.
As can be seen in the code (see below), the `searchNode` helper function will return `null` in some cases and all of its call-sites should protect against that before attempting to access the returned data.
While only one of these changes were necessary to fix the breaking errors in issue 13756, in order to prevent future bugs I've added similar defensive code throughout this file.
- 07955fa1d3/src/core/xfa/som.js (L169)
- 07955fa1d3/src/core/xfa/som.js (L239)
- 07955fa1d3/src/core/xfa/som.js (L254)
For e.g. `gulp mozcentral`, the *built* `pdf.worker.js` file decreases from `1 837 608` to `1 834 907` bytes with this patch-series.
The improvement comes first of all from less overall indentation in `PDFFunction`, and secondly from the removal of (now) unnecessary indirection in the code.
*This follows the exact same princial as PR 12083, but for the `PDFFunction` parsing instead.*
Given that the IR format is completely unused now, all that the current code does is add a bunch of unnecessary indirection/overhead to the handling of PDF-functions.
With this patch, the `PDFPageProxy.getOperatorList` method will now return `PDFOperatorList`-instances that also include Annotation-operatorLists (when those exist). Hence this closes a small, but potentially confusing, gap between the `render` and `getOperatorList` methods.
Previously we've been somewhat reluctant to do this, as explained below, but given that there's actual use-cases where it's required probably means that we'll *have* to implement it now.
Since we still need the ability to separate "normal" rendering operations from direct `getOperatorList` calls in the worker-thread, this API-change unfortunately causes the *internal* renderingIntent to become a bit "messy" which is indeed unfortunate (note the `"oplist-"` strings in various spots). As-is I suppose that it's not all that bad, but we may want to consider changing the *internal* renderingIntent to e.g. a bitfield in the future.
Besides fixing issue 13704, this patch would also be necessary if someone ever tries to implement e.g. issue 10165 (since currently `PDFPageProxy.getOperatorList` doesn't include Annotation-operatorLists).
*Please note:* This patch is *also* tagged "api-minor" for a second reason, which is that we're now including the Annotation-id in the `beginAnnotation` argument. The reason for this is to allow correlating the Annotation-data returned by `PDFPageProxy.getAnnotations`, with its corresponding operatorList-data (for those Annotations that have it).
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!
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.
With the changes in PR 13687 we're now checking if `target` is defined *twice* in a row, which shouldn't be necessary :-)
(I noticed this when glancing at the unofficial LGTM results; maybe we should re-evalute the decision to not integrate that into the CI.)
