Fix bug in dprintf - isdigit had sign overflow problem.

diff --git a/src/output.c b/src/output.c
index ff190f8e6d2d93ad8e8711b97717e5df33526149..b09677e4b8a93e1a9db1364499ff5916fac458b1 100644 (file)
--- a/src/output.c
+++ b/src/output.c
@@ -148,7 +148,7 @@ puthex(u16 action, u32 val)
 static inline int
 isdigit(u8 c)
 {
-    return c - '0' < 10;
+    return ((u8)(c - '0')) < 10;
 }
 
 static void