From a22bb86fe02e00bb493e7aecba85f93508ade87e Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Wed, 29 Jul 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-07-29

---
 port/alloc.c  | 7 ++++---
 port/devbit.c | 2 ++
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/port/alloc.c b/port/alloc.c
index e1a1d153b0ef5e76a33b32ba9ec65f6b775dcbc5..4ef0b3764004d7a07aa2078283ca19d1c0698168 100644
--- a/port/alloc.c
+++ b/port/alloc.c
@@ -130,12 +130,12 @@ xspanalloc(ulong size, int align, ulong span)
 	ulong a, p, sinc;
 	ulong ptr[Spanlist];
 
-	sinc = span/8;
+	sinc = size/8;
 	span = ~(span-1);
 	for(i = 0; i < Spanlist; i++) {
 		p = (ulong)xalloc(size+align);
 		if(p == 0)
-			panic("xspanalloc: %d %d %lux", size, align, span);
+			break;
 
 		a = p+align;
 		a &= ~(align-1);
@@ -150,7 +150,8 @@ xspanalloc(ulong size, int align, ulong span)
 		ptr[i] = (ulong)xalloc(sinc);
 	}
 	USED(sinc);
-	panic("xspanalloc: spanlist");		
+	xsummary();
+	panic("xspanalloc: %d %d %lux\n", size, align, span);	
 	return 0;
 }
 
diff --git a/port/devbit.c b/port/devbit.c
index 9efd84b75bcfac563fa2ae164e8069ea8d50a190..5fd69178c61ac9abdaf22b1d4ba8eaa819befe6d 100644
--- a/port/devbit.c
+++ b/port/devbit.c
@@ -1411,6 +1411,8 @@ bitwrite(Chan *c, void *va, long n, ulong offset)
 			v = BGSHORT(p+1);
 			if(v<0 || v>=bit.nfont || (ff=bit.font[v])==0)
 				error(Ebadblt);
+			if(ff->b == 0)
+				error(Ebadbitmap);
 			l = BGSHORT(p+3);
 			if(l >= ff->ncache)
 				error(Ebadblt);