[abhishekfdd]

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wp_get_missing_image_subsizes() reads $image_meta['width'] and $image_meta['height'] without checking that they exist. For attachments whose metadata lacks dimensions (SVGs added by plugins, broken uploads, migrated content), this triggers "Undefined array key" warnings.

This PR uses isset() checks so that missing dimensions fall back to 0. The return value is unchanged; only the warning is removed. With a zero dimension, image_resize_dimensions() rules out every sub-size, so the function still returns an empty array, and the result still passes through the wp_get_missing_image_subsizes filter exactly as before.

Testing

New test class Tests_Media_wpGetMissingImageSubsizes:

• 4 missing-dimension cases (SVG with no dimensions, JPEG with no dimensions, JPEG with no width, JPEG with no height): on trunk all 4 fail with the Undefined array key "width" / Undefined array key "height" warning; with this fix all 4 pass.
• Filter test: asserts the wp_get_missing_image_subsizes filter is still called, receiving an empty array and the attachment ID, when width/height are missing.
• Control test: an image with valid dimensions still reports missing sub-sizes (e.g. thumbnail).

Commands:

npm run test:php -- --filter Tests_Media_wpGetMissingImageSubsizes
npm run test:php -- --group media
npm run test:php -- --group image

All pass. phpcs is clean on both changed files.

Trac ticket: https://core.trac.wordpress.org/ticket/57813

Use of AI Tools

AI assistance: Yes
Tool(s): Claude Code
Model(s): Claude Opus 5.5
Used for: Local environment setup, running tests, implementing the fix, adding the filter test, and coding-standards cleanup; the changes were reviewed by me.

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