altos/scheme: Allow unicode in lexer

[fw/altos] / src / scheme / ao_scheme_string.c

diff --git a/src/scheme/ao_scheme_string.c b/src/scheme/ao_scheme_string.c
index c49e1e325c9872a97634614afdf6a6669d8774bc..2c6d096000d43d759c9d7a276ad5ad1c88dcafcc 100644 (file)
--- a/src/scheme/ao_scheme_string.c
+++ b/src/scheme/ao_scheme_string.c
@@ -47,6 +47,8 @@ ao_scheme_string_alloc(int len)
 {
        struct ao_scheme_string *s;
 
+       if (len < 0)
+               return NULL;
        s = ao_scheme_alloc(len + 2);
        if (!s)
                return NULL;
@@ -182,8 +184,8 @@ ao_scheme_string_write(FILE *out, ao_poly p, bool write)
                                fputs("\\\\", out);
                                break;
                        default:
-                               if (c < ' ')
-                                       fprintf(out, "\\%03o", c);
+                               if ((uint8_t) c < ' ')
+                                       fprintf(out, "\\%03o", (uint8_t) c);
                                else
                                        putc(c, out);
                                break;