From a41b74059bcb40e7fc37f3da72758b89cde4c437 Mon Sep 17 00:00:00 2001
From: Ori Bernstein <ori@eigenstate.org>
Date: Sat, 17 Oct 2020 18:59:36 -0700
Subject: [PATCH] upas: fix appendfolder timestamps (thanks umbraticus)

When moving messages between folders, mbappend,
deliver, and nedmail were trying to parse the
timestamp ouut of the message. They were doing
it incorrectly, trying to include the user name
as part of the date format.

Change to pass just the date to the date parser.
---
 sys/src/cmd/upas/common/folder.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/sys/src/cmd/upas/common/folder.c b/sys/src/cmd/upas/common/folder.c
index f16e2212c..0e39b9ddd 100644
--- a/sys/src/cmd/upas/common/folder.c
+++ b/sys/src/cmd/upas/common/folder.c
@@ -184,8 +184,8 @@ mboxesc(Biobuf *in, Biobuf *out, int type)
 int
 appendfolder(Biobuf *b, char *addr, int fd)
 {
-	char *s;
-	int r, n;
+	char *s, *t;
+	int r;
 	Biobuf bin;
 	Folder *f;
 	Tzone *tz;
@@ -194,15 +194,27 @@ appendfolder(Biobuf *b, char *addr, int fd)
 	f = getfolder(b);
 	Bseek(f->out, 0, 2);
 	Binit(&bin, fd, OREAD);
+
 	s = Brdstr(&bin, '\n', 0);
-	n = strlen(s);
-	if(!s || strncmp(s, "From ", 5) != 0){
+
+	/* Unix from */
+	if(s != nil && strncmp(s, "From ", 5) == 0
+	&& (t = strchr(s + 5, ' ')) != nil
+	&& tmparse(&tm, Timefmt, t + 1, nil, nil) != nil){
+		f->t = tmnorm(&tm);
+	}else {
+		/*
+		 * Old mailboxes have dates in ctime format,
+		 * which contains ambiguous timezone names.
+		 * Passing in the local timezone has the side
+		 * effect of disambiguating the timezone name
+		 * as local.
+		 */
 		tz = tzload("local");
 		tmtime(&tm, f->t, tz);
 		Bprint(f->out, "From %s %τ\n", addr, tmfmt(&tm, Timefmt));
-	}else if(n > 5 && tmparse(&tm, Timefmt, s + 5, nil, nil) != nil)
-		f->t = tmnorm(&tm);
-	if(s)
+	}
+	if(s != nil)
 		Bwrite(f->out, s, strlen(s));
 	free(s);
 	r = mboxesc(&bin, f->out, f->type);