fix: pin the Imagick coder per provider without a temporary file (OC10-164) - #41834
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oc-tmueller merged 7 commits intoSep 16, 2026
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isDangerousToDecode() (af3c147) is a deny-list over the libmagic-sniffed type, but the decode that follows re-derives the format independently: readImageBlob() with no format set consults Imagick's own ~130-entry magic table, so the coder actually invoked can differ from what the mime check reasoned about. application/postscript and application/pdf are deliberately not denied - Postscript and PDF legitimately decode them - which means PostScript-looking bytes still pass the gate through every other Bitmap provider (SGI, Font, Illustrator, Photoshop, TIFF, Heic), and Imagick's own sniffing then hands them to the Ghostscript delegate anyway. Pin the coder each provider actually expects instead of leaving Imagick to guess: getImagickFormat() maps a provider's own detected mime type(s) to an explicit Imagick format name, and getResizedPreview() installs it with setFormat() before readImageBlob(), so no temporary file is involved and the content never leaves memory. setFormat() pins the wand's output format as well as the input coder, so both setImageFormat('png') and setFormat('png') are needed afterwards - otherwise getThumbnail()'s (string) cast re-encodes back to the pinned input format and hands back the original bytes. That one missing call is what previously made setFormat() look as though it skipped rasterization altogether. It does decode: verified against unpinned geometry for tiff/psd/sgi/ai/heic/ttf on both ImageMagick 6.9.11-60 with imagick 3.8.1 and ImageMagick 7.1.1-36 with imagick 3.7.0. The pin is deliberately not guarded by queryFormats(): if a build does not register the coder a provider needs, throwing is correct, because the only alternative is falling back to the content-sniffing this pin exists to prevent. Heic pins HEIC for both image/heic and image/heif, as they are one container handled by one coder module and not every build registers a distinct HEIF coder. Office.php pins through its constructor argument instead. A "FORMAT:path" prefix there pins only the input coder and leaves the output format alone, so its setImageFormat('jpg') needs no counterpart. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com>
SVG::getThumbnail() is the one Imagick read path in core that is not a Bitmap provider, and it had the same gap: ImagickFactory sets svg:sanitize, svg:embed and svg:decode, but the read that follows let Imagick pick the coder from the content, so those options could be reasoning about a different coder than the one that ran. Pin SVG explicitly, and reset both the image and wand output formats to png32 afterwards for the same reason as Bitmap.php - setFormat() pins the output format as well, so setImageFormat() alone would leave getImageBlob() re-encoding back to SVG. Unlike Bitmap.php the pin is guarded by queryFormats(). A build that registers no SVG coder cannot be pinned to it and cannot decode SVG at all either way, so throwing would trade a clear "no decode delegate" failure for a confusing "Unable to set format" one; owncloudci/php:8.3 is such a build. The value at risk is also lower here: what gets pinned is DOMSanitizer's serialized output, not the raw file bytes. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com>
…-164)
Adds CoderPinningTest, which asserts both halves of the pin: every provider
still decodes its own format, and PostScript content is rejected by the
providers it is foreign to (SGI, Photoshop, TIFF, Heic) rather than being
handed to the Ghostscript delegate by ImageMagick's own content-sniffing.
Six fixtures had to be added - tests/data had no .ai/.heic/.psd/.sgi/.tiff/
.ttf sample at all, so there was nothing to decode per provider. The HEIC
fixture is AVIF-encoded on purpose: ImageMagick classifies the avif brand as
HEIC, and an HEVC-encoded sample needs a libde265 delegate that is not
present everywhere.
Skips are per-coder rather than blanket. The tests these are modelled on
gated on Imagick::queryFormats('SVG') as a stand-in for "this build has the
extended coder set", but owncloudci/php:8.3 registers no SVG coder at all,
so that guard skipped every case and the assertions never ran in CI. Each
case now requires only the one coder it exercises, which is also why the
image/heif case runs here: it pins HEIC, so it no longer depends on a
distinct HEIF coder being registered.
testPinnedDecodeReturnsPngAndNotThePinnedInputFormat covers the one
non-obvious part of the mechanism - setFormat() pins the output format as
well, and for TIFF the re-encode is byte-identical to the input, so dropping
the second setFormat() call would be easy to reintroduce and hard to notice.
SanitizeTest needs the mime type plumbed through, since providers now pin
based on it. Its skip guard moves to the PDF/TTF coders its two providers
actually use - it deliberately does not require an SVG coder, because the
whole point of those cases is that the content never reaches Imagick.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com>
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Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes. |
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com>
5 tasks
CoderPinningTest reported the wrong thing on any ImageMagick build differing from the one it was written against, which matters for the pending PHP 7.4 backport: tests/phpunit-autotest.xml sets failOnRisky, and PHPUnit 9.6 defaults beStrictAboutTestsThatDoNotTestAnything to true, so a test executing zero assertions is a hard failure rather than a warning. testFontNeverInvokesADangerousCoderForForeignContent kept its only assertion inside `if ($result !== false)`. On any build where FreeType refuses the PostScript payload outright - the safest outcome, and the one the test exists to assert about - it executed no assertion at all and failed as risky. Both outcomes now collapse into one branch-free assertion. requireCoder() proves a coder is registered, not that the delegate behind it can decode a given fixture. coders/heic.c registers HEIC, HEIF and AVIF whenever libheif is present, but decoding the AVIF fixture additionally needs an AV1 decoder inside libheif, so a build without one failed instead of skipping. requireDecodableFixture() reads the fixture unpinned first and skips when the build cannot decode those bytes at all, since the pinned read failing then says nothing about the pin. The fixture stays AVIF-branded deliberately: an AVIF-branded file served by the Heic provider, which pins HEIC for it, is exactly the case worth a real sample. The negative tests could also pass for the wrong reason. isDangerousToDecode() is a deny-list over the sniffed type and it denies text/*, so a libmagic build reporting the payload as text/plain would reject it at that gate before the coder pin ever ran. assertPayloadReachesTheCoderPin() asserts the sniffed type, so such a build fails loudly with an actionable message instead of passing vacuously. The payload itself was duplicated in both tests and is now a constant. Both fixtures the Font and Illustrator cases used are replaced by files already in the tree. testimage.ttf was Microsoft Verdana, carrying an "All Rights Reserved" notice and a trademark notice, so the Font case now reads the Apache-2.0 core/fonts/OpenSans-Regular.ttf instead - same sfnt tag, same DSIG table, same coder path. testimage.ai was byte-identical to testimage.pdf, and ImageMagick's AI coder is a Ghostscript alias for the PDF one, so the Illustrator case reads testimage.pdf directly. Fixture paths now resolve through OC::$SERVERROOT, the existing idiom in tests/lib. CoderPinningTest and SanitizeTest both call Imagick::queryFormats() unguarded, which raises a class-not-found Error rather than skipping on a build without ext-imagick. Both get the @requires annotation the neighbouring provider tests already use. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com>
Three neighbouring preview tests guarded on the wrong thing, in ways the coder
pin makes load-bearing.
PDFTest gated on Imagick::queryFormats('SVG'), a coder the PDF provider never
touches. On any build registering no SVG coder - owncloudci/php:8.3 among them -
all four cases skipped while reporting "No PDF provider present", so the PDF
preview assertions never ran in CI even though the PDF coder was present. It now
requires PDF, the coder PDF::getImagickFormat() actually pins.
SVGTest names the right coder but compared the count to exactly 1, which skips
whenever a build registers SVG alongside SVGZ or MSVG. It now checks for zero,
matching the idiom the rest of the directory uses.
BitmapTest had no coder guard at all. It drives Postscript against testimage.eps,
which now hard-requires the EPS coder rather than reaching one through
ImageMagick's own sniffing, so on a reduced build it would fail instead of
skipping. It now requires EPS.
SanitizeTest's guard goes the other way and is removed entirely.
isDangerousToDecode() rejects that content before ImagickFactory::create() and
before setFormat(), so those eight cases never reach a coder - requiring PDF and
TTF could only ever let a reduced build skip the OC10-164 regression assertions
silently, which is the failure mode this whole series is trying to remove.
The changelog entry also now records that pinning costs previews for files whose
extension does not match their content, since media types come from the
extension. That is the intended trade-off, but it is user-visible.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com>
…(OC10-164) The coder pin reads $file->getMimeType(), not the mime type that selected the provider. Those differ whenever a caller overrides the selection type through getThumbnail(['mimeType' => ...]): apps/files_trashbin/ajax/preview.php does, because a trashed file's .d<timestamp> suffix defeats extension-based detection and leaves the node reporting application/octet-stream, and apps/dav forwards the request's query parameters straight through. Using the file's own type is deliberate - a request cannot steer it, which is the property the pin depends on. The cost is that an implementation is handed mime types it does not serve, and must still decode; returning a constant coder does that correctly. That is easy to mistake for a bug and "tighten" by rejecting any mime type which fails the provider's own getMimeType() regex. Doing so would reject every trashbin bitmap preview - tif, psd, sgi, heic, ai, pdf and eps alike - to fix one case. Three cases now assert the opposite, each first asserting that the mime type really does fail the provider's regex so they cannot pass vacuously. Font is the only provider whose coder depends on the argument, so it is the only place the divergence is observable: a .pfb not stored as application/x-font gets no preview. Deciding from content instead would mean re-deriving the format from magic bytes, which is what the pin exists to avoid, so this is recorded rather than fixed. Comments only in lib/; no behaviour change. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com>
oc-tmueller
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* test: stub the mime type in BitmapStreamTest so it survives the coder pin BitmapStreamTest mocks OCP\Files\File without stubbing getMimeType(), so the mock returns null. That is harmless today, but #41827 has Bitmap providers read the mime type to decide which Imagick coder to pin, and getResizedPreview() declares it as string - null there is a TypeError, which being an \Error escapes getThumbnail()'s \Exception handler rather than degrading to no preview. Merging #41827 would therefore turn these cases red on master. The success case also decoded a PNG through the Photoshop provider, which only works while ImageMagick is free to sniff the format. Once Photoshop pins the PSD coder, a PNG stops decoding and the case fails for a reason that has nothing to do with the stream. It now uses the PDF provider against testimage.pdf, so the provider, the file's mime type and the content all agree and the success path stays a success either way - guarded on the PDF coder, since pinning makes that a hard requirement. Verified against both trees: on master 3 tests / 5 assertions, and on master merged with #41827 the full tests/lib/Preview/ suite is 79 tests / 215 assertions / 0 failures, where before this change it reported 2 errors. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: decode a self-written TIFF rather than gating on the PDF coder Imagick::queryFormats('PDF') reports that the coder was compiled in. It says nothing about whether a PDF can actually be decoded: it consults neither the coder rights in policy.xml nor the presence of the Ghostscript delegate. On an image that revokes the PDF coder - the ImageMagick hardening OC10-164 is itself driving - or one without the gs binary, the guard passes, readImageBlob() throws, and the case fails red over an environment difference rather than over the stream handling it exists to check. That is the same mistake as gating a test on a coder the provider never uses, which this series has been removing elsewhere. The success case now writes its own TIFF through Imagick and decodes it through the TIFF provider. TIFF needs no external delegate, and a build cannot disagree with itself about a blob it just produced, so the remaining skip fires only where TIFF is unavailable altogether - in which case no assertion here could run anyway. It also drops a fixture dependency. The comments claiming that the mime type is read and that XML is rejected before any coder is consulted described the coder-pin change on #41827, which is not in this tree. They now say what happens here and what they anticipate. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: probe the TIFF read path, not just the write path, before asserting The guard added in the previous commit wrote a TIFF and treated that as proof the build could handle TIFF. ImageMagick grants coder rights per direction, so a policy of rights="write" for TIFF lets the blob be produced, declines to skip, and then fails red on the decode - reintroducing exactly the failure the guard exists to remove. It now reads the blob back inside the guard, so what is probed is what the assertion needs. Verified by revoking TIFF read in a throwaway container: the case skips with a clear message instead of failing. The guard also caught only \ImagickException, while ImagickPixelException extends \Exception directly and is a sibling rather than a subclass, so a pixel-wand failure would have escaped as an error rather than the intended skip. It now catches \Exception, and the Imagick handles are released in finally blocks rather than only on the success path - which matters in a test about releasing handles. Finally, the claim that no coder is consulted for the XML payload was wrong: ImageMagick's SVG coder claims any blob opening with "<?xml" and then fails on a document with no <svg> root. The comment now says that, and warns that another XML payload is not automatically substitutable. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: skip only when TIFF is absent, and assert the stream before the decode The round-trip probe added in the previous commit closed one hole by opening another: it turned any TIFF failure into a skip, and a skip here costs the success-path fclose() assertion - which is the OC10-164 stream-leak guard itself. A guard quietly withholding these assertions is exactly how they came to never run in CI, so a misconfiguration should be loud, not green. The guard is now the single condition that is genuinely an absent feature rather than a broken setup: no TIFF coder registered at all. Revoked coder rights, an unparsable policy.xml or a wand that cannot be constructed all fail. TIFF can be held to that standard because no stock policy revokes it, unlike PDF, which Debian and Ubuntu deny out of the box - the reason this uses a TIFF in the first place. The stream assertion also moves ahead of the decode assertion, so an environment that cannot decode the blob still exercises the handle release under test and still reports the decode as the failure. Verified by revoking TIFF read in a throwaway container: all five assertions run, and the failure names the decode. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: separate an absent TIFF delegate from a denied one by ImageMagick's message The previous commit gated on Imagick::queryFormats('TIFF'), on the assumption that registration implies support. It does not: coders/tiff.c registers TIFF, TIF and TIFF64 unconditionally and only assigns the decoder and encoder pointers when built against libtiff, while GetMagickList() behind queryFormats() matches on the coder name alone. A build without libtiff therefore reports TIFF as registered, declines to skip, and - with the catch removed by that same commit - errors instead. That is the fourth variant of one mistake in this file: checking something adjacent to what the assertion needs. There is no registration check that can tell an absent feature from a broken setup, so this stops using a proxy and reads what ImageMagick reports. A missing delegate yields "no encode delegate for this image format" (or the decode equivalent) and skips; a policy denial yields "not allowed by the security policy" and is re-thrown, along with anything else. Both directions are probed, since coder rights are granted per direction. The success-path assertion message is also outcome-neutral now. It runs before the decode assertion, so it fires when the decode failed too, and must not claim the leak was on the success path when the decode is the actual defect. Verified in throwaway containers: a normal build passes; a policy revoking TIFF is loud rather than skipped; and MagickCore's message catalogue carries both delegate strings this matches on. The missing-delegate branch is matched against that catalogue rather than executed, since this build has libtiff. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: keep both TIFF guards, since neither covers the other's case The previous commit swapped the queryFormats() check for a message check when the two are complementary. Without libtiff, a modular ImageMagick - Debian and Ubuntu configure --with-modules - never builds coders/tiff.so, so TIFF is not registered and setImageFormat() fails with php-imagick's own "Unable to set the image format" before any delegate is consulted. That matches neither delegate substring, so it was rethrown and turned a build with no TIFF feature red. queryFormats() is what catches that case; the message check catches the non-modular build, which registers TIFF regardless and fails later at the delegate. Both are back. Also records two limits instead of implying they do not exist. A module- or coder-domain policy denial can surface as MissingDelegateError, textually identical to an absent delegate, so such a build skips - the classifier only rejects messages that name a policy outright rather than guessing. And an allowlist-style policy.xml denying all but a few coders fails here, which is the accepted cost of being loud about misconfiguration; the note explaining why TIFF rather than PDF is restored alongside it. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: fail the undecodable case on bytes no coder claims The payload was '<?xml version="1.0"?><notanimage>x</notanimage>', which is not environment-independent. ImageMagick's IsSVG() claims any blob opening with "<?xml", so readImageBlob() reported "no decode delegate for this image format `SVG'" - it threw only because these images register no SVG renderer. Where librsvg or the internal MSVG renderer is present, the lenient parser returns a blank canvas rather than throwing, and the case would fail for reasons unrelated to the stream. That is the same environment coupling this file has been shedding elsewhere; the failure path had it too. It now uses bytes no coder claims. ImageMagick sniffs the format as "" and fails with "no decode delegate for this image format `'" on every build regardless of which delegates are compiled in. libmagic reads them as application/octet-stream rather than text, so they also survive #41827's mime gate and still reach the decode on that branch instead of being turned away earlier. Verified in a container: the old payload sniffs as SVG, the new one as "", and both the master tree and the tree merged with #41827 stay green. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * docs: correct the recorded reasons in BitmapStreamTest's comments Three claims in these docblocks were wrong, and the payload rationale was the one that mattered: it said an XML payload "would throw only where no SVG renderer is registered" and would otherwise return a blank canvas. Measured in three builds - stock, with libmagickcore-6.q16-6-extra installed, and with the policy opened up - it throws in all of them, as "no decode delegate `SVG'", then "not allowed by the security policy `MVG'", then MVG's own "must specify image size". The coder is MVG rather than SVG too. So the reason to prefer bytes no coder claims is not that the XML payload is unusable, it is that its failure reason varies by build and that libmagic reads it as text/xml, which #41827's mime gate rejects before the decode. The comment now says that, so nobody rules out a working option on a wrong premise. The read-back rationale claimed both directions get denied; what actually happens with TIFF rights revoked is that getImageBlob() still returns a blob and only the read raises - which is the argument for probing the read, now stated as measured. The mime-type stub was described as anticipating #41827 and reading as speculative, when omitting it is precisely what turned that PR red. It is stated as a requirement instead, so it does not invite deletion once the pin lands. Also trims the libtiff explanation. It asserted ImageMagick internals no assertion here pins and which differ across major versions, and it is where the errors above were concentrated; the two-check rationale and the PDF-vs-TIFF choice stay. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: pin why the undecodable case throws, and assert the handle first Both assertions in testClosesTheStreamWhenDecodingThrows are satisfied by any early return from getThumbnail(), and nothing tied the failure to the decode. That matters on #41827, which adds a pre-decode mime gate denying text/*: a build whose libmagic read these bytes as text would refuse them before any coder, leave this test green, and quietly stop covering the path the test is named for. The detected media type is now asserted, so that drift fails instead of hiding. The two tests also disagreed on assertion order. PHPUnit stops at the first failure, so asserting the result first meant an unexpectedly decodable payload would mask a co-occurring leak - the handle being the regression guard this file exists for. testClosesTheStreamOnSuccess already ordered it the other way and said why; the failure case now matches. The payload rationale claimed the sniffed format is "", which holds here but not under the pin, where nothing is sniffed and the pinned coder rejects the header instead. Both throw without depending on the build's delegates, which is the actual property being relied on, so the comment says that rather than one tree's mechanism. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: decode a PSD, dropping the TIFF availability guard entirely Every guard in this file existed because the success case used TIFF, and TIFF can be absent: coders/tiff.so links libtiff. PSD cannot be absent for that reason - coders/psd.so links no image library at all, ImageMagick implements the format natively - and the Photoshop provider was already here for the failure case. So the success case now writes and decodes a PSD, and the whole apparatus goes: no queryFormats() check, no write-then-read-back probe, no message classifier separating an absent delegate from a denied one, and no docblock asserting ImageMagick internals that nothing pins. The test is unconditional, which is what it should have been throughout - a skip would retire the success-path fclose() assertion, and a guard quietly withholding assertions is how the OC10-164 preview tests came to never run in CI to begin with. The file loses 44 lines. This also removes a contradiction with the branch it is written to be compatible with: CoderPinningTest::requireDecodableFixture() skips on a policy denial where the classifier here rethrew, so the same suite gave two answers for the same coder. Verified: unconditional pass on master and on the tree merged with the pin, and still red when the finally that releases the handle is removed. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * test: assert the gate's own condition, and stub the third mock's mime type Two narrow corrections. The pin on the payload's detected type asserted one exact classification, application/octet-stream, while the gate it protects only refuses text/*, image/svg*, application/xml and image/x-mvg. A libmagic that matched these bytes to some other binary magic entry would still reach the decode exactly as intended and fail the assertion, which is the build-dependence this file has been shedding. It now mirrors isDangerousToDecode()'s own condition. The mime type is also stubbed on the cannot-be-opened mock, so that case does not depend on where in getThumbnail() the mime type is first read. That stub does not make the file runnable on a tree without #41835's fopen guard, and the comment no longer claims it does - measured on #41827's branch, which carries neither that guard nor the finally, the suite reports 1 error and 1 failure because every case here asserts what those two added. Failing there is correct, and it is why this lands on master rather than folded into #41834: CI builds the head-into-base merge commit, which always contains both. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * docs: scope the master-only claim, and name the deny-list this mirrors Two comment corrections, no code change. "Every case here asserts behaviour the guard and the finally introduced" is wrong for testClosesTheStreamOnSuccess: fclose() on the success path predates #41835, which only moved it into the finally, so that case passes on a tree without either. The measurement already said so - one error and one failure on #41834's branch, two cases and not three - and the claim should have been scoped to those two. The pre-decode check is also now attributed to its source, OC\Preview\Bitmap:: isDangerousToDecode(), which #41834 adds and which is private and so cannot be called from a test. Mirroring it is still preferable to pinning one exact libmagic classification, but the duplication has a cost worth stating: if that deny-list gains an entry, this copy must gain it too, or the payload starts being refused at the gate while the assertion stays green and the decode goes uncovered. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * docs: name the change that actually drifts, and drop merge-strategy prose Two more comment corrections. The maintenance note pointed the wrong maintainer at the mirror. A new text/ entry in isDangerousToDecode()'s deny-list is already matched by the text/ prefix here, so mirroring it would be busywork; the change that actually drifts is an entry of the application/xml or image/x-mvg shape, which the prefix does not catch. It now says that. isDangerousToDecode()'s own comment also enumerates what it already covers rather than anticipating additions, so that clause is gone. The claim that CI building the head-into-base merge commit is why this belongs on master rather than folded into #41834 was a non-sequitur - that same fact means folding it in would have been green too, since the failures only appear on the bare branch. The real reason is that the branch tree lacks #41835 and so cannot run the file locally, which the surrounding lines already say. Merge-strategy reasoning does not belong in a test docblock in any case; it goes in the pull request. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> * docs: state the drift rule against all three of the mirrored rules The previous wording named only the text/ prefix and treated a drifting deny-list entry as necessarily an exact match. The mirror has three rules, and an entry written as a prefix - application/postscript alongside the existing image/svg, say - drifts just as badly while a reader following that wording concludes no mirroring is needed. It also over-warned in the other direction: an added image/svg+xml is not matched by text/ but is already matched by the image/svg prefix, so it does not drift. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> --------- Signed-off-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> Co-authored-by: Thomas Müller <323649642+oc-tmueller@users.noreply.github.com> Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
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Summary
Implements Florian's coder-pinning fix for OC10-164 entirely in memory. Replaces #41832, which does the same pinning but needs a temporary file per preview (and a new
/dev/shm-backedITempManager::getRamTemporaryFile()to make that affordable).Stacked on #41827's branch rather than master, since it touches the same files. This is a sibling of #41832, not a follow-up — #41832 will be closed.
Why #41832 needed a temp file, and why it turns out it doesn't
#41832 pins via
readImage('TIFF:/path'), which needs a real filesystem path, becausesetFormat()+readImageBlob()appeared to pin correctly but skip rasterization —getImageBlob()handed back the original, undecoded bytes.That diagnosis was wrong.
setFormat()does fully decode. It also sets the wand's output format, sogetImageBlob()was faithfully re-encoding back to the pinned input format, andsetImageFormat('png')alone could not override it. For TIFF and SGI that re-encode is byte-identical to the input, which is exactly why it looked like untouched passthrough. PSD was the tell: 15016 bytes out for a 14988-byte input.The fix is one extra call —
setFormat('png')on the wand alongsidesetImageFormat('png')on the image.Verified on two builds, comparing pinned geometry against an unpinned read as ground truth:
Why removing the temp file matters
/dev/shmis 64 MB by default in bothowncloud/server:10.15.0andowncloudci/php:8.3(measured), deployments routinely set it smaller, andpreview_max_filesize_imagedefaults to 50 MB. A full tmpfs makesfile_put_contents()short-write, andreadImage('TIFF:…')frequently succeeds on a truncated TIFF/PSD/SGI stream — so a partially rendered image would be written to the preview cache and served from then on. There is no way to detect that fromis_dir()/is_writable(), since a full tmpfs at mode 1777 is still writable.Not writing the file at all removes that failure mode rather than hardening it, and with it the
ramtempdirectoryconfig surface, theOCP\ITempManageraddition (a BC break in a patch release), and the tmpfs leak thatcleanOld()could not sweep.What changed
Bitmap::getResizedPreview()takes the file's own mime type, callssetFormat($this->getImagickFormat($mimeType))beforereadImageBlob(), and resets both output formats afterwards.abstract protected getImagickFormat(string $mimeType): stringwith one implementation per provider.SVG.phpgets the same pin,Office.phpkeeps pinning through its constructor argument.queryFormats()inBitmap: if a build does not register a provider's coder, throwing is correct — the only alternative is the content-sniffing the pin exists to prevent.SVG.phpis guarded, because a build with no SVG coder cannot decode SVG either way and what it pins is DOMSanitizer output, not raw bytes.HeicpinsHEICfor bothimage/heicandimage/heif. They are one container handled by one coder module, and pinningHEIFbroke.heifpreviews on every build that registers onlyHEIC— includingowncloudci/php:8.3.Diff is +89/-4 across 11 source files, and it is PHP 7.4-clean, so the pending 10.16 backport (#41828) needs no syntax changes.
Tests
CoderPinningTestasserts both halves of the pin, with six new fixtures (tests/datahad no.ai/.heic/.psd/.sgi/.tiff/.ttfsample at all). The HEIC fixture is AVIF-encoded on purpose — ImageMagick classifies theavifbrand as HEIC, and an HEVC sample needs a libde265 delegate that is not present everywhere.These skips are now per-coder, which fixes a real gap. The tests this file is modelled on gated every case on
Imagick::queryFormats('SVG')as a stand-in for "this build has the extended coder set" — butowncloudci/php:8.3registers no SVG coder, so the whole file skipped and the assertions never ran in CI. Each case now requires only the coder it exercises. Onowncloudci/php:8.3the result is 15 tests executing rather than skipping, including theimage/heifcase.SanitizeTest's guard likewise moves to the PDF/TTF coders its providers actually use; it deliberately does not require an SVG coder, since the point of those cases is that the content never reaches Imagick.Known residuals (unchanged, pre-existing)
AI/PDF/EPSaccept PostScript content — same Ghostscript family, so it is not foreign to them. Bounded to those three providers and mitigated by fix: harden ImageMagick policy and install rsvg-convert (OC10-164) owncloud-docker/php#309'spolicy.xml, which denies MVG/MSL/MSVG regardless of entry point.TTF/PFBaccept non-font bytes, but the TTF coder is what runs: the output is the same 800x480 font specimen sheet a real TTF produces, so there is no coder handoff. Covered bytestFontNeverInvokesADangerousCoderForForeignContent.abstract protected getImagickFormat()is a load-time fatal for any out-of-treeOC\Preview\Bitmapsubclass.Bitmapislib/private, and the compile-time guarantee that every provider declares its coder seems worth more — flagging it as the one deliberate BC risk.Verification
tests/lib/Preview/+TempManagerTest+PreviewManagerTeston a freshowncloudci/php:8.3: 73 tests, 171 assertions, 0 failures. The only skips are pre-existingPDFTest/SVGTestones.php-cs-fixerwith the ownCloud standard: 0 of 41 files need fixing.php -lunder PHP 7.4 for every changed file.