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Merged
brow merged 6 commits into from
Jul 20, 2026
Merged

fix(mobile): image upload fails due to unstripped metadata #2185

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8f01bf3
fix(mobile): scrub UIKit image metadata
Jul 20, 2026
7fbdaac
fix(mobile): scope media policy copy to images
Jul 20, 2026
6743f4e
fix(mobile): tighten image upload error copy
Jul 20, 2026
507ef90
fix(mobile): preserve wide-gamut image colors
Jul 20, 2026
65dad5e
fix(mobile): normalize sanitizer data slices
Jul 20, 2026
f386aba
docs(media): record UIKit fixture provenance
Jul 20, 2026
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fix(mobile): preserve wide-gamut image colors 
Co-authored-by: npub1ft62tztwwm2x9xamk25smmuaj4sfckdkldksruf2x2jwqalffkrq0g7arr <4af4a5896e76d4629bbbb2a90def9d95609c59b6fb6d01f12a32a4e077e94d86@sprout-oss.stage.blox.sqprod.co>
Signed-off-by: npub1ft62tztwwm2x9xamk25smmuaj4sfckdkldksruf2x2jwqalffkrq0g7arr <4af4a5896e76d4629bbbb2a90def9d95609c59b6fb6d01f12a32a4e077e94d86@sprout-oss.stage.blox.sqprod.co>
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npub1ft62tztwwm2x9xamk25smmuaj4sfckdkldksruf2x2jwqalffkrq0g7arr
npub1ft62tztwwm2x9xamk25smmuaj4sfckdkldksruf2x2jwqalffkrq0g7arr committed Jul 20, 2026
commit 507ef9031152057a5b673dc938ea553a73f1019b
22 changes: 19 additions & 3 deletions mobile/ios/Runner/MediaSanitizer.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -15,23 +15,39 @@ enum MediaSanitizer {
static func sanitizeImage(_ image: UIImage, mimeType: String) throws -> Data? {
switch mimeType {
case "image/png":
guard let encoded = image.pngData() else { return nil }
guard let image = renderInSRGB(image), let encoded = image.pngData() else { return nil }
return try scrubPng(encoded)
case "image/jpeg":
return try encodeJpeg(image)
case "image/webp":
guard let encoded = image.pngData() else { return nil }
guard let image = renderInSRGB(image), let encoded = image.pngData() else { return nil }
return try scrubPng(encoded)
default:
return nil
}
}

static func encodeJpeg(_ image: UIImage) throws -> Data? {
guard let encoded = image.jpegData(compressionQuality: 1.0) else { return nil }
guard
let image = renderInSRGB(image),
let encoded = image.jpegData(compressionQuality: 1.0)
else {
return nil
}
return try scrubJpeg(encoded)
}

private static func renderInSRGB(_ image: UIImage) -> UIImage? {
guard image.size.width > 0, image.size.height > 0 else { return nil }
let format = UIGraphicsImageRendererFormat()
format.scale = image.scale
format.opaque = false
format.preferredRange = .standard
return UIGraphicsImageRenderer(size: image.size, format: format).image { _ in
image.draw(in: CGRect(origin: .zero, size: image.size))
}
}

static func scrubPng(_ data: Data) throws -> Data {
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guard data.count >= pngSignature.count, data.prefix(pngSignature.count) == pngSignature else {
throw MediaSanitizationError.invalidPng
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73 changes: 73 additions & 0 deletions mobile/ios/RunnerTests/RunnerTests.swift
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Expand Up @@ -102,6 +102,79 @@ class RunnerTests: XCTestCase {
XCTAssertNotNil(UIImage(data: encoded))
}

func testSanitizeDisplayP3ImagePreservesRenderedColorInSRGB() throws {
let image = try displayP3Image(red: 0.9, green: 0.2, blue: 0.1)
let expectedColor = try sRGBPixel(from: image)
let mimeTypesAndAccuracy: [(mimeType: String, accuracy: UInt8)] = [
("image/png", 0), ("image/jpeg", 1),
]

for (mimeType, accuracy) in mimeTypesAndAccuracy {
let sanitized = try XCTUnwrap(
MediaSanitizer.sanitizeImage(image, mimeType: mimeType),
"Failed to sanitize Display-P3 image as \(mimeType)"
)

try assertMatchesRelayImageMetadataPolicy(sanitized, mimeType: mimeType)
let decoded = try XCTUnwrap(UIImage(data: sanitized))
XCTAssertEqual(
decoded.cgImage?.colorSpace?.name,
CGColorSpace(name: CGColorSpace.sRGB)?.name
)
let actualColor = try sRGBPixel(from: decoded)
XCTAssertEqual(actualColor.count, expectedColor.count)
for (actual, expected) in zip(actualColor, expectedColor) {
XCTAssertLessThanOrEqual(
actual > expected ? actual - expected : expected - actual,
accuracy
)
}
}
}

private func displayP3Image(red: CGFloat, green: CGFloat, blue: CGFloat) throws -> UIImage {
let colorSpace = try XCTUnwrap(CGColorSpace(name: CGColorSpace.displayP3))
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedLast.rawValue)
let context = try XCTUnwrap(
CGContext(
data: nil,
width: 1,
height: 1,
bitsPerComponent: 8,
bytesPerRow: 4,
space: colorSpace,
bitmapInfo: bitmapInfo.rawValue
)
)
context.setFillColor(
try XCTUnwrap(CGColor(colorSpace: colorSpace, components: [red, green, blue, 1]))
)
context.fill(CGRect(x: 0, y: 0, width: 1, height: 1))
return UIImage(cgImage: try XCTUnwrap(context.makeImage()))
}

private func sRGBPixel(from image: UIImage) throws -> [UInt8] {
let colorSpace = try XCTUnwrap(CGColorSpace(name: CGColorSpace.sRGB))
var bytes = [UInt8](repeating: 0, count: 4)
let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.premultipliedLast.rawValue)
let context = try bytes.withUnsafeMutableBytes { bytes in
try XCTUnwrap(
CGContext(
data: bytes.baseAddress,
width: 1,
height: 1,
bitsPerComponent: 8,
bytesPerRow: 4,
space: colorSpace,
bitmapInfo: bitmapInfo.rawValue
)
)
}
context.interpolationQuality = .none
context.draw(try XCTUnwrap(image.cgImage), in: CGRect(x: 0, y: 0, width: 1, height: 1))
return bytes
}

private func fixtureData(named name: String, extension fileExtension: String) throws -> Data {
let url = try XCTUnwrap(
Bundle(for: RunnerTests.self).url(forResource: name, withExtension: fileExtension))
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