diff --git a/sys/man/1/sam b/sys/man/1/sam
index f107b3c79..e197c0c4c 100644
--- a/sys/man/1/sam
+++ b/sys/man/1/sam
@@ -835,8 +835,10 @@ used.
 The snarf buffer is unaffected.
 .TP
 .B <rio>
-Exchange snarf buffers with
+Exchange dot with snarf buffer of
 .IR rio .
+If dot is the null string, the text in the snarf buffer is
+used.
 .TP
 .BI / regexp
 Search forward for the next match of the last regular expression
diff --git a/sys/src/9/imx8/gic.c b/sys/src/9/imx8/gic.c
index 6c3052e1d..f96a04d5d 100644
--- a/sys/src/9/imx8/gic.c
+++ b/sys/src/9/imx8/gic.c
@@ -265,7 +265,7 @@ intrenable(int irq, void (*f)(Ureg*, void*), void *a, int tbdf, char *)
 	prio = 0x80;
 	intid = irq;
 	if((v = xalloc(sizeof(Vctl))) == nil)
-		panic("irqenable: no mem");
+		panic("intrenable: no mem");
 	v->irq = irq;
 	v->intid = intid;
 	v->f = f;
diff --git a/sys/src/cmd/upas/Mail/mbox.c b/sys/src/cmd/upas/Mail/mbox.c
index 60fdc7dee..b7bdeda83 100644
--- a/sys/src/cmd/upas/Mail/mbox.c
+++ b/sys/src/cmd/upas/Mail/mbox.c
@@ -802,6 +802,8 @@ changemesg(Plumbmsg *pm)
 
 	digest = plumblookup(pm->attr, "digest");
 	action = plumblookup(pm->attr, "mailtype");
+	if(digest == nil || action == nil)
+		return;
 	if(strcmp(action, "new") == 0){
 		if((m = load(pm->data, digest, 1)) == nil)
 			return;