test custom editor opens a readonly file

[kendfss]

Greetings, folks!

I was setting up a new machine with the helix editor (as offered by winget install Helix.Helix) and when clicking the Test Custom Editor button in the installation dialogue I found that the file to be edited was opened in readonly mode and even a !w could do nothing about it.

edit - sorry if this is intended behaviour and consequently a helix issue

[Neel14151926535897]

i am angry!

[rimrul]

The file seems to be created owned by the Administrators group, whereas the current user has only read and execute permissions on the file.

[dscho]

The code backing the Test Custom Editor button lives here. And indeed, it simply calls the SaveStringToFile() function to create that file:

    SaveStringToFile(TmpFile,InputText,False);

This SaveStringToFile() function is documented thusly:

Prototype:

function SaveStringToFile(const FileName: String; const S: AnsiString; const Append: Boolean): Boolean;

Description:

Saves the specified string to the specified file. If Append is True and the specified file already exists, it will be appended to instead of overwritten. Returns True if successful, False otherwise.

Remarks:

This function does not automatically write a line break before or after the string. If Append is True and the existing file did not end in a line break, the function will effectively append to the existing last line. To avoid this you can put line break characters before and/or after your string:

SaveStringToFile('c:\filename.txt', #13#10 + 'the string' + #13#10, True);

It does not say anything specifically about permissions, and I think the actual culprit might be the location of the file: {tmp}\editor-test.txt. That {tmp} expands to:

Temporary directory used by Setup or Uninstall. This is not the value of the user's TEMP environment variable. It is a subdirectory of the user's temporary directory which is created by Setup or Uninstall at startup (with a name like "C:\WINDOWS\TEMP\IS-xxxxx.tmp"). All files and subdirectories in this directory are deleted when Setup or Uninstall exits. During Setup, this is primarily useful for extracting files that are to be executed in the [Run] section but aren't needed after the installation.

I could imagine that the best solution for this might be to change the permissions of this file, specifically, using an Exec() call in the {tmp} directory that executes icacls to give all authenticated users full permissions on that temporary file.

[dscho]

I will give Copilot a chance to work on this, and will specifically note: @Copilot, the PR will need to be opened in the build-extra repository and modify the installer/install.iss file.

[dscho]

I will give Copilot a chance to work on this [...]

... or not, it is not available in the git-for-windows org.

[dscho]

I will give Copilot a chance to work on this [...]

... or not, it is not available in the git-for-windows org.

Once you look in the correct place, it's actually there... ;-)

But obviously, @Copilot failed to heed my instruction to open the PR in the build-extra repository, not in the git repository.

[dscho]

I opened git-for-windows/build-extra#618 to fix this, going for a different approach because even changing the permissions on the file does not change the permissions on the directory, and editors like vim want to write by creating a new file and then atomically renaming it to the original filename.

[dscho]

/add relnote bug Git for Windows' installer used a non-writable file for testing custom editors, which was fixed.

The workflow run was started