Didn't look that far back (2014!)

While fixing bug #53298 I stumbled upon the fact that when overwriting files with new contents that are shorter than previous contents, trailing cruft is preserved after the last write action.
Workarounds include overwriting the trailing cruft with spaces, or writing to another file and renaming it afterwards. Both workarounds look overly involved.

It would be easier if there were a way to truncate a file.

Options:

- a dedicated function, say ftrunc(), that by default truncates at the current file pointer or accepts a position where the file should be truncated.

- an option for fclose() to truncate the file during the closing action.