Selecting an Image from bottom to top throws exceptions

[ac-newcomp]

📝 Provide detailed reproduction steps (if any)

1. Navigate to https://ckeditor.com/docs/ckeditor5/latest/features/image.html
2. Go to the sample with an image and add a newline below it
3. Select the image, starting from bottom to top
4. See GIF below for demonstration

✔️ Expected result

No errors thrown

❌ Actual result

The following error is thrown: Uncaught CKEditorError: model-selection-range-intersects: Trying to add a range that intersects with another range in the selection. Read more: https://ckeditor.com/docs/ckeditor5/latest/framework/guides/…port/error-codes.html#error-model-selection-range-intersects {"addedRange":{"start":{"root":"main","path":[4],"stickiness":"toNext"},"end":{"root":"main","path":[5,73],"stickiness":"toPrevious"}},"intersectingRange":{"start":{"root":"main","path":[4,0,0],"stickiness":"toNone"},"end":{"root":"main","path":[4,0,0],"stickiness":"toNone"}}}

📃 Other details

• Browser: FF79.0
• OS: Windows 10
• CKEditor version: all version that I've tested, including whatever version is on the CKEditor document page
• Installed CKEditor plugins: Image

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[FilipTokarski]

Hi, thanks for the report. I confirm this bug.
Apparently it was introduced in 20.0.0, bisection shows this commit 824d731

[Reinmar]

My guess:

1. FF creates a multi-range selection in this case. At least, it did that in the past.
2. Our post-fixer fixes one of these selections by e.g. extending it so it overlaps now with the other range.
3. Error.

If I'm right, we could consider merging overlapping selections.

[psmyrek]

Firefox creates a multi-range selection containing three ranges, two of which are identical. The selection post-fixer tries to merge all of them together, but the rangeA.isIntersecting( rangeB ) returns false for identical ranges. As a result, the selection returned from post-fixer contains not properly merged, intersected ranges.

[LangQian]

In FF (Win & Mac), with similar steps, this issue also happens to Horizontal Line

[psmyrek]

Yes, the Horizontal Line is also affected. My PR #8466 is a general fix for all such cases.