Bug 110993 – ImageDocument 's incorrect zoom behavior.

• Status: UNCONFIRMED
• Component: Images

[Kibeom Kim]

To reproduce the bug:
1. Visit an image e.g., https://www.webkit.org/images/icon-gold.png
2. Make the browser window(rendering area)'s height and width about 3 times bigger than the image.
3. Zoom in several times using keyboard shortcut (e.g., ctrl + '+' in Linux Chrome)
4. Zoom back to the original state (100%) using keyboard shortcut (e.g., ctrl + '-' in Linux Chrome)

Expected behavior:
The image size after Step 4. is identical to the image size at Step 1.

Observed behavior:
The image size after Step 4. is bigger than the image size at Step 1.


This is a bug in ImageDocument.cpp so it is reproducible on any browser and any platform.

[Kibeom Kim]

I fixed the bug, and it will be submitted soon.

[Kibeom Kim]

Created attachment 190791 [details]
Patch

[Kibeom Kim]

Comment on attachment 190791 [details]
Patch

I tried to make a testcase under LayoutTests but I couldn't, because ImageDocument class is used when browser opens an image, not html, and also it behaves differently if it is inside <iframe>. So I just attached a manual test.

[Tim Horton]

Comment on attachment 190791 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=190791&action=review

> Source/WebCore/ChangeLog:3
> +        Fix ImageDocument 's zoom bug.

This is not a great title. It should be more descriptive. ImageDocument could easily have many "zoom bugs", I'm not sure how this title tells me which one you're fixing.

> Source/WebCore/ChangeLog:7
> +

Please add a comment here explaining why your change makes sense.

[Ahmad Saleem]

Blink commit - https://chromium.googlesource.com/chromium/blink/+/a0a9d50d5a3c886cbbd2f8599d237e332e0ce5fa