TYPO3 Core

I rechecked with 6.2.10 and patch set 3 of #65358 applied:

You are right, both versions render out file:// and file:/// links correctly in FE and the links also survive re-opening and re-saving the CE in RTE.

The difference is how the RTE shows those links in HTML mode after re-opening.
Without the above patch, the HTML code is shown very weird (HTTP scheme added, domain added, url-encoded):

<a href="http://www.mydomain.com/?file:%2F%2F%2Fmy%2Fpath%2Fmyfile.pdf" class="external-link-new-window" title="Opens external link in new window">my link text</a>

WITH the above patch the HTML code in RTE is clean:

<a href="file:///my/path/myfile.pdf" class="external-link-new-window" title="Opens external link in new window" data-htmlarea-external="1" rtekeep="1">my link text</a>

A severe problem that I now discovered is that NEITHER of these two versions can be re-opened with the link tool in RTE!
Instead they both result in a popup window with an error page "Oops, an error occurred! File /my/path/myfile.pdf/ does not exist." (I made sure the file DOES exist.)
So editors have no possibility to change existing file:// links.

I will try to nail down this problem and see, whether rtekeep is actually needed to make the link tool work with existing file:// links, or whether it also works with the strangely encoded links that the system currently shows in RTE's HTML mode.

I have in RTE:

<p><a href="file://my/path/file.txt" data-htmlarea-external="1">Test</a></p>

The file doesn't exists, but browser pops up without any error. Can you try to recreate the link with the both patches applied?

Nicole, I am very sorry for waisting your time.
I did not understand that #65358 contains two patches for branch 6.2. To be honest, even after re-reading the updates I am still confused by the numbering of the patch sets and I could only find all fragments by opening each set and comparing the changed files.

But now I have implemented all changes of that issue into 6.2.10 and I am happy to report that all problems with file:// links in RTE are resolved.
Works like a charm!

Please close this issue.
Sorry again.