upas/fs plumb modify for self-made flag changes

[theinicke@bss-wf.de]

[-- Attachment #1: Type: text/plain, Size: 592 bytes --]

Currently upas/fs plumbs modify messages only if the flag changes are made by another imap connection. If the flag changes are made within the running upas/fs no modify message is plumbed.

Assuming this is not intentionally and we want to get a modify plumb message after flags were changed in running upas/fs the attached patch fixes this by making sure to send a modify for pending changes upon mbox sync.

The modify could be plumbed earlier, but this way it costs us almost nothing and changed flags from outside upas/fs are noticed in the same time interval anyway.

--
Tobias Heinicke

[-- Attachment #2.1: Type: text/plain, Size: 326 bytes --]

from postmaster@9pi:
The following attachment had content that we can't
prove to be harmless.  To avoid possible automatic
execution, we changed the content headers.
The original header was:

	Content-Disposition: attachment; filename=upasfs.patch
	Content-Type: text/plain; charset="US-ASCII"
	Content-Transfer-Encoding: 7bit

[-- Attachment #2.2: upasfs.patch.suspect --]
[-- Type: application/octet-stream, Size: 306 bytes --]

diff -r 8857059a1805 sys/src/cmd/upas/fs/fs.c
--- a/sys/src/cmd/upas/fs/fs.c	Fri Jan 31 09:25:39 2020 -0800
+++ b/sys/src/cmd/upas/fs/fs.c	Sat Feb 01 13:22:38 2020 +0100
@@ -1197,6 +1197,7 @@
 			mb->modflags(mb, m, f);
 		m->flags = f;
 		m->cstate |= Cidxstale;
+		m->cstate |= Cmod;
 	}
 	return nil;
 }