add russian charset support

Reference: /n/sources/patch/applied/upasfs-russian-charset
Date: Tue Feb  8 05:00:41 CET 2005

--- /sys/src/cmd/upas/fs/fs.c	Tue Feb  8 05:00:40 2005
+++ /sys/src/cmd/upas/fs/fs.c	Tue Feb  8 05:00:40 2005
@@ -1363,6 +1363,8 @@
 	{ "iso-8859-2",		10,	2, "8859-2", },
 	{ "big5",		4,	2, "big5", },
 	{ "iso-2022-jp",	11, 2, "jis", },
+	{ "windows-1251",	12,	2, "cp1251"},
+	{ "koi8-r",		6,	2, "koi8"},
 };
 
 int
--- /sys/src/cmd/upas/fs/mbox.c	Tue Feb  8 05:00:41 2005
+++ /sys/src/cmd/upas/fs/mbox.c	Tue Feb  8 05:00:40 2005
@@ -1132,6 +1132,24 @@
 			m->bend = x + len;
 			m->ballocd = 1;
 		}
+	} else if(cistrcmp(s_to_c(m->charset), "windows-1251") == 0){
+		len = xtoutf("cp1251", &x, m->body, m->bend);
+		if(len != 0){
+			if(m->ballocd)
+				free(m->body);
+			m->body = x;
+			m->bend = x + len;
+			m->ballocd = 1;
+		}
+	} else if(cistrcmp(s_to_c(m->charset), "koi8-r") == 0){
+		len = xtoutf("koi8", &x, m->body, m->bend);
+		if(len != 0){
+			if(m->ballocd)
+				free(m->body);
+			m->body = x;
+			m->bend = x + len;
+			m->ballocd = 1;
+		}
 	}
 
 	m->converted = 1;