Fix: prevent malformed URL error when parsing IP:PORT by adding defau…

[surelyruchi]

PR Description

This PR fixes an issue where URLs containing IP addresses with ports (e.g., 8.8.8.8:443) were being treated as malformed due to the absence of a URI scheme (http://, https://, etc.).

Related Issues

• Closes URL with IP:PORT returns malformed URL error #841

Checklist

• I have gone through the contributing guide
• I have updated my branch and synced it with project main branch before making this PR
• I am using the latest Flutter stable branch (run flutter upgrade and verify)
• I have run the tests (flutter test) and all tests are passing

Added/updated tests?

We encourage you to add relevant test cases.

• Yes
• No, and this is why: This is a small, focused fix , tests will be added later if required based on usage or feedback.

OS on which you have developed and tested the feature?

• Windows
• macOS
• Linux

[surelyruchi]

Hey @ashitaprasad @animator, this is a minor change in the code. Could you take a quick look and share your thoughts when you get a chance?

Basically, the issue was URL's like 8.8.8.8:443 without scheme passing through Uri.parse(url) treats it as a string and returns null value which resulted to malformed url and previously default scheme were getting added if the URL matched kLocalhostRegex which only handled localhost.
So I added a generic regex check to add missing URL scheme if missing from such address.

[animator]

Sure. We will review the code.