Whitespace handling issues with pasted page searches

[wknapik]

Description

When using page search (^f), a pasted search string gets transformed right in the search field, with no indication to the user, and occurrences of the modified string are matched.

Whitespace is stripped on both sides, but a search for any combination of whitespace characters alone becomes a search for a single space.

This makes certain searches impossible/results incorrect - such as when searching for a tab (or many), or searching for text indented by some number of tabs, or with trailing tabs. The same applies to spaces when pasted, but not when typed in (which is a bit more problematic for tabs).

There is a workaround - if a search string is pasted with whitespace in the middle, it is preserved and if the characters around the whitespace are removed, a search for whitespace in any location in the search string becomes possible and the matches are correct.

However, occurrences of tabs are not highlighted, unless the text containing them is selected.

And lastly, this is just a consequence of the above - if the workaround is used (or the search string is typed in manually) to successfully search for text with whitespace on either side and the search string is selected and copied from the search field and pasted back, it becomes a different search string - with whitespace stripped on both ends, so the actual matches change.

Steps to Reproduce

1. Open a page, or file containing spaces and tabs in the browser
2. Hit ^f
3. Paste search strings containing whitespace on either side

Actual result:

See: above

Expected result:

There's a few issues here. Tabs should be highlighted when found. As for the rest - a checkbox on the search field to preserve surrounding whitespace could be a solution.

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave	1.45.118 Chromium: 107.0.5304.91 (Official Build) (64-bit)
Revision	3d5948960d62418160796d5831a4d2d7d6c90fa8-refs/branch-heads/5304@{#1097}
OS	Linux

Version/Channel Information:

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? Yes

Miscellaneous Information:

Arch Linux

[wknapik]

Another issue with match highlighting in page search #26281.