Don't allow reading from channel numbers less than 0

As that results in us trying to read from before the beginning of the file array
jmalak · Nov 26, 2024 · 83453db · 83453db
1 parent dd46500
commit 83453db
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/kermit/k95/ckuus7.c b/kermit/k95/ckuus7.c
@@ -12230,6 +12230,8 @@ z_in(channel,s,buflen,length,flags)
       return(z_error = FX_NOP);
     if (channel >= z_maxchan)
       return(z_error = FX_CHN);
+    if (channel < 0)
+      return(z_error = FX_CHN);
     if (!z_file[channel])
       return(z_error = FX_NOP);
     if (!(t = z_file[channel]->z_fp))