Please add code project tags - thanks!

These all seem to be triggered from .jpg images shot on a Nikon COOLPIX AW100 camera, which apparently uses a bogus non-numeric value for the EXIF GPSAltitudeRef tag, which is *supposed* to be set to either 0 and 1: https://exiftool.org/TagNames/GPS.html

As far as I can tell, the COOLPIX didn't even have GPS, so I don't know why it would be generating this tag in the first place. Anyway, patch forthcoming.

Change 639635 had a related patch set uploaded (by C. Scott Ananian; owner: C. Scott Ananian):
[mediawiki/core@master] media: Support GPSAltitudeRef exif tag

https://gerrit.wikimedia.org/r/639635

Change 639505 had a related patch set uploaded (by Brennen Bearnes; owner: C. Scott Ananian):
[mediawiki/core@wmf/1.36.0-wmf.16] media: Support GPSAltitudeRef exif tag

https://gerrit.wikimedia.org/r/639505

Change 639505 merged by jenkins-bot:
[mediawiki/core@wmf/1.36.0-wmf.16] media: Support GPSAltitudeRef exif tag

https://gerrit.wikimedia.org/r/639505

Mentioned in SAL (#wikimedia-operations) [2020-11-05T23:29:38Z] <brennen@deploy1001> Synchronized php-1.36.0-wmf.16/languages/i18n/exif: Backport: [[gerrit:639505|media: Support GPSAltitudeRef exif tag - i18n/exif files (T267370)]] (duration: 01m 08s)

Mentioned in SAL (#wikimedia-operations) [2020-11-05T23:38:27Z] <brennen@deploy1001> Synchronized php-1.36.0-wmf.16/includes/media/FormatMetadata.php: Backport: [[gerrit:639505|media: Support GPSAltitudeRef exif tag - FormatMetData.php (T267370)]] (duration: 07m 22s)

So I looked into this a bit more, without the time pressure of being a train blocker.
Turns out that the images in question have perfectly valid GPSAltitudeRef tags:

>>> $e2 = BitmapMetadataHandler::Jpeg('/home/cananian/Downloads/Melaleuca_calycina.jpg');

=> [
     "ImageDescription" => "OLYMPUS DIGITAL CAMERA         ",
     "Make" => "OLYMPUS CORPORATION    ",
     "Model" => "TG-4            ",
[...]
     "GPSLatitude" => -33.629423333333,
     "GPSLongitude" => 120.14593833333,
     "GPSAltitudeRef" => "\0",
     "GPSStatus" => "A",
     "GPSImgDirectionRef" => "M",
     "GPSImgDirection" => "2400/100",
     "GPSVersionID" => "0.0.3.2",
   ]

Granted, the value is being reported as \0 and/or \1 instead of 0 or 1, but that is similar to how other "byte" fields in EXIF are reported by PHP. However, look what happens when that same file is accessed via instant commons:

>>> $f2 = RepoGroup::singleton()->findFile(Title::newFromText('File:Melaleuca_calycina.jpg'));
=> ForeignAPIFile {#3599
     +repo: ForeignAPIRepo {#2741
       +fetchDescription: true,
       +descriptionCacheExpiry: 43200,
       +name: "wikimediacommons",
     },
   }
>>> unserialize($f2->getMetadata());
=> [
     "ImageDescription" => "OLYMPUS DIGITAL CAMERA         ",
     "Make" => "OLYMPUS CORPORATION    ",
     "Model" => "TG-4            ",
     "Orientation" => 1,
[...]
     "GPSLatitude" => -33.629423333333,
     "GPSLongitude" => 120.14593833333,
     "GPSAltitudeRef" => "�",
     "GPSStatus" => "A",
     "GPSImgDirectionRef" => "M",
     "GPSImgDirection" => "2400/100",
     "GPSVersionID" => "0.0.3.2",
     "MEDIAWIKI_EXIF_VERSION" => 2,
   ]
>>>

Apparently there are two things going on here:

1. In Exif.php we have the following code:

		if ( isset( $this->mFilteredExifData['GPSAltitude'] )
			&& isset( $this->mFilteredExifData['GPSAltitudeRef'] )
		) {
			// We know altitude data is a <num>/<denom> from the validation
			// functions ran earlier. But multiplying such a string by -1
			// doesn't work well, so convert.
			list( $num, $denom ) = explode( '/', $this->mFilteredExifData['GPSAltitude'] );
			$this->mFilteredExifData['GPSAltitude'] = $num / $denom;

			if ( $this->mFilteredExifData['GPSAltitudeRef'] === "\1" ) {
				$this->mFilteredExifData['GPSAltitude'] *= -1;
			}
			unset( $this->mFilteredExifData['GPSAltitudeRef'] );
		}

but for these files GPSAltitude is reported as 0/0 (aka invalid/missing) and so is deleted. The way this conditional is written, if GPSAltitude is removed, then GPSAltitudeRef will always stick around.

2. When fetching foreign file metadata using ForeignAPIFile, the metadata is fetched with:

		$data = $repo->fetchImageQuery( [
			'titles' => 'File:' . $title->getDBkey(),
			'iiprop' => self::getProps(),
			'prop' => 'imageinfo',
			'iimetadataversion' => MediaHandler::getMetadataVersion(),
			// extmetadata is language-dependant, accessing the current language here
			// would be problematic, so we just get them all
			'iiextmetadatamultilang' => 1,
		] );

and you can see the output at:
https://commons.wikimedia.org/w/api.php?action=query&format=json&prop=imageinfo&titles=File%3AMelaleuca_calycina.jpg&iiprop=timestamp%7Cuser%7Ccomment%7Curl%7Csize%7Csha1%7Cmetadata%7Cmime%7Cmediatype%7Cextmetadata

{
    "batchcomplete": "",
    "query": {
        "normalized": [
            {
                "from": "File:Melaleuca_calycina.jpg",
                "to": "File:Melaleuca calycina.jpg"
            }
        ],
        "pages": {
            "73667274": {
                "pageid": 73667274,
                "ns": 6,
                "title": "File:Melaleuca calycina.jpg",
                "imagerepository": "local",
                "imageinfo": [
                    {
                        "timestamp": "2018-10-17T02:25:50Z",
                        "user": "Gderrin",
                        "size": 2974608,
                        "width": 4608,
                        "height": 3456,
                        "comment": "User created page with UploadWizard",
                        "url": "https://upload.wikimedia.org/wikipedia/commons/9/9a/Melaleuca_calycina.jpg",
                        "descriptionurl": "https://commons.wikimedia.org/wiki/File:Melaleuca_calycina.jpg",
                        "descriptionshorturl": "https://commons.wikimedia.org/w/index.php?curid=73667274",
                        "sha1": "5e36db0fef7d2d1bf91b76797b9be2816f567127",
                        "metadata": [
                            {
                                "name": "ImageDescription",
                                "value": "OLYMPUS DIGITAL CAMERA         "
                            },
[...]
                            {
                                "name": "GPSLatitude",
                                "value": -33.629423333333335
                            },
                            {
                                "name": "GPSLongitude",
                                "value": 120.14593833333333
                            },
                            {
                                "name": "GPSAltitudeRef",
                                "value": "\ufffd"
                            },
                            {
                                "name": "GPSStatus",
                                "value": "A"
                            },
                            {
                                "name": "GPSImgDirectionRef",
                                "value": "M"
                            },
                            {
                                "name": "GPSImgDirection",
                                "value": "2400/100"
                            },
                            {
                                "name": "GPSVersionID",
                                "value": "0.0.3.2"
                            },
                            {
                                "name": "MEDIAWIKI_EXIF_VERSION",
                                "value": 1
                            }
                        ],
[...]

Note that the \0 from the original metadata array has been "corrupted" to \uFFFD by the action API (and this happens in JSON, XML, PHP, and other API formats).

Most likely we should just be deleting the GPSAltitudeRef tag unconditionally, since it is always being handled as part of GPSAltitude. But if there are other EXIF tags which raw byte values (type self::UNDEFINED in Exif.php) then they will need to be processed into a form that can survive the transit across the imageinfo API.

Change 639834 had a related patch set uploaded (by C. Scott Ananian; owner: C. Scott Ananian):
[mediawiki/core@master] media: Filter out GPSAltitudeRef exif tag

https://gerrit.wikimedia.org/r/639834

Change 639635 merged by jenkins-bot:
[mediawiki/core@master] media: Support GPSAltitudeRef exif tag

https://gerrit.wikimedia.org/r/639635

5 more of these errors on commons after deploy of 1.36.0-wmf.16 to group1. Coming in at at a slower rate.

For these images:

• https://commons.wikimedia.org/wiki/File:Podlaskie_-_Bra%C5%84sk_-_Bra%C5%84sk_-_Bielska_v-NE_201109003_01.JPG
• https://commons.wikimedia.org/wiki/File:Eichst%C3%A4tt_Residenz_06_Treppenhaus.jpg
• https://commons.wikimedia.org/wiki//wiki/File:Moscow_metro_Nizegorodskaya_20200629_213117_4.jpg?uselang=ru
• https://commons.wikimedia.org/wiki//wiki/File:Podlaskie_-_Bielsk_Podlaski_-_Plutycze_-_S-Ctr_-_v-N.JPG
• https://commons.wikimedia.org/wiki//wiki/File:Husarentempel_M%C3%B6dling_360%C2%B0_Rundblick_am_Abend_zur_Stadt_Wien.jpg

Change 639834 merged by jenkins-bot:
[mediawiki/core@master] media: Filter out GPSAltitudeRef exif tag

https://gerrit.wikimedia.org/r/639834

Change 640247 had a related patch set uploaded (by C. Scott Ananian; owner: C. Scott Ananian):
[mediawiki/core@master] media: EXIF SubSecTime* are text not numeric

https://gerrit.wikimedia.org/r/640247

Change 640249 had a related patch set uploaded (by C. Scott Ananian; owner: C. Scott Ananian):
[mediawiki/core@master] Temporarily disable EXIF non-numeric tag value warnings

https://gerrit.wikimedia.org/r/640249

Change 640254 had a related patch set uploaded (by C. Scott Ananian; owner: C. Scott Ananian):
[operations/mediawiki-config@master] Turn on formatnum logging

https://gerrit.wikimedia.org/r/640254

Change 640248 had a related patch set uploaded (by C. Scott Ananian; owner: C. Scott Ananian):
[mediawiki/core@master] media: Support Google panorama EXIF extensions

https://gerrit.wikimedia.org/r/640248

Change 640247 merged by jenkins-bot:
[mediawiki/core@master] media: EXIF SubSecTime* are text not numeric

https://gerrit.wikimedia.org/r/640247

Change 640248 merged by jenkins-bot:
[mediawiki/core@master] media: Support Google panorama XMP properties

https://gerrit.wikimedia.org/r/640248

Change 640488 had a related patch set uploaded (by Brennen Bearnes; owner: C. Scott Ananian):
[mediawiki/core@wmf/1.36.0-wmf.16] Downgrade the severity of the non-numeric argument to formatNum warnings

https://gerrit.wikimedia.org/r/640488

Change 640249 merged by jenkins-bot:
[mediawiki/core@master] Downgrade the severity of the non-numeric argument to formatNum warnings

https://gerrit.wikimedia.org/r/640249

Change 640488 merged by jenkins-bot:
[mediawiki/core@wmf/1.36.0-wmf.16] Downgrade the severity of the non-numeric argument to formatNum warnings

https://gerrit.wikimedia.org/r/640488

Change 640254 merged by jenkins-bot:
[operations/mediawiki-config@master] Turn on formatnum logging

https://gerrit.wikimedia.org/r/640254

Mentioned in SAL (#wikimedia-operations) [2020-11-10T20:10:41Z] <brennen@deploy1001> Synchronized wmf-config/InitialiseSettings.php: Config: [[gerrit:640254|Turn on formatnum logging (T267587, T267370)]] (duration: 01m 02s)

Mentioned in SAL (#wikimedia-operations) [2020-11-10T20:27:25Z] <brennen@deploy1001> Started scap: Backport: [[gerrit:640487|language: Honor $wgTranslateNumerals, even if PHP does digit translation(T267614)]] and [[gerrit:640488|Downgrade the severity of the non-numeric argument to formatNum warnings (T267370, T267587)]]

Mentioned in SAL (#wikimedia-operations) [2020-11-10T21:02:06Z] <brennen@deploy1001> Finished scap: Backport: [[gerrit:640487|language: Honor $wgTranslateNumerals, even if PHP does digit translation(T267614)]] and [[gerrit:640488|Downgrade the severity of the non-numeric argument to formatNum warnings (T267370, T267587)]] (duration: 34m 46s)

@xd0bx: did you intend to assign this to another user? Have you discussed with them?