fix: Write in a temp file before replacing the original file, fixes #903

[Midou36O]

I'm not experienced in rust but i thought saving in a temporary file would help avoid corrupting the original file if the save fails. Tested on my laptop and it does avoid corrupting the original file, which is the intended behavior.
This should fix #903

[Doublonmousse]

This also fixes #1128

[Midou36O]

( Mini bump in case it got missed, or needs changes :p )

[Doublonmousse]

This looks good!
Initially, something similar was explored in #1177, but as this other PR touches on the file format (and we don't want to change it every morning) it'll take time before this other PR is merged.

So it makes sense to merge this PR as it fixes your issue now, knowing that this may be refactored further down the line when it comes time to merge #1177.

The only concern is how this change affect the file watcher, so that we don't have a "file modified on disk" when saving and keep the protection of the window not closing until the file is actually saved #1096. (So some testing is in order to verify this isn't affected)

[Doublonmousse]

I'm testing so see whether this works well with the file watcher and I'm encountering an issue. For now I'm doing the following

• open rnote
• edit the document
• save to a new document
• wait for the save to finish/popups to disappear (success!)
• CTRL + S again

• "Opened file was removed" and rnote treats the opened tab as a yet-to-be saved.

This is expected because the file watcher sees the file being removed when replacing the file and acts on it. It's actually the same thing for writing to the file (the file watcher sees the file being modified/written to) but its output is suppressed by doing

self.set_output_file_expect_write(true);

and preventing anything happening here (so that we don't see that the file is modified on disk when saving)

rnote/crates/rnote-ui/src/canvas/mod.rs

Lines 1012 to 1015 in 8db8dc1

	if canvas.output_file_expect_write() {
	// While writing is in progress, multiple modify events might occur.
	return;
	}

(and a little further down here

rnote/crates/rnote-ui/src/canvas/mod.rs

Lines 1074 to 1077 in 8db8dc1

	if canvas.output_file_expect_write() {
	// Own file writing has finished
	canvas.set_output_file_expect_write(false);
	}

)

So you probably need to check what kind of events get sent in that enum when saving a file for the second time and suppress this additional event

[anesthetice]

You might be interested in this:

• https://github.com/flxzt/rnote/pull/1177/files#diff-e1e60757edbac1f4d8741ee8fa9d64ae21ec07d180c4b01b455e854f29782fe2
• https://github.com/flxzt/rnote/pull/1177/files#diff-69e14b6632502e3ecc34bc99cab25aebed4717bb0b288df3f5f8fb96808827a4

But basically to get around the file watcher issue I just set the output file to the "new" one:

self.set_output_file(Some(gio::File::for_path(&filepath)));

[Midou36O]

Thanks, I just don't have time right to look into it right now but once I get back to it I'll try to replicate what you've done.