parsenum: Signedness issues.

char can be signedness, and using signedness types is dangerous - it can
lead to negative offsets when doing table lookups. We apparently should just
ban char usage.

1 files changed, 2 insertions, 2 deletions

diff --git a/py/parsenumbase.c b/py/parsenumbase.c
index 0057e467e5..ce140655bd 100644
--- a/py/parsenumbase.c
+++ b/py/parsenumbase.c
@@ -31,7 +31,7 @@
 // find real radix base, and strip preceding '0x', '0o' and '0b'
 // puts base in *base, and returns number of bytes to skip the prefix
 int mp_parse_num_base(const char *str, uint len, int *base) {
-    const char *p = str;
+    const byte *p = (const byte*)str;
     int c = *(p++);
     if ((*base == 0 || *base == 16) && c == '0') {
         c = *(p++);
@@ -63,6 +63,6 @@ int mp_parse_num_base(const char *str, uint len, int *base) {
         }
         p--;
     }
-    return p - str;
+    return p - (const byte*)str;
 }