[Oberon] pcreceive.sh not working for files that are multiples of 255

[Paul Reed]

Hi Andreas,

> I do not really understand 100% the part starting with
> "int pos = (rxcount - fnlen -1) % 256, followed by two cascaded if
> statements, one with condition pos == 0 and one with condition flen >
> 255".

Nor did I, even though I wrote it :(  However, after sitting down with my
former self and getting him to explain himself, I have tested the
following patch (on macOS, at least; the latter diff just gets rid of a
warning).

The rxcount variable tracks how many characters have been "received" by
the *virtual* machine, which is why it's % 256 not % 255 (took me a
while...).

So a packet header byte is "received" every 256 bytes, or (now) when the
remaining file length (flen) is zero, otherwise it's a data byte.  That's
what the if statement *should* have said.  Apologies!

Thanks again,
Paul


diff --git a/src/pclink.c b/src/pclink.c
index 5c4aa81..fa9ce3d 100644
--- a/src/pclink.c
+++ b/src/pclink.c
@@ -101,18 +101,18 @@ static uint32_t PCLink_RData(const struct
RISC_Serial *serial) {
       }
     } else {
       int pos = (rxcount - fnlen - 1) % 256;
-      if (pos == 0) {
+      if (pos == 0 || flen == 0) {
         if (flen > 255) {
           ch = 255;
         } else {
           ch = (uint8_t)flen;
+          if (flen == 0) {
+            mode = 0; unlink(RecName);
+          }
         }
       } else {
         read(fd, &ch, 1);
         flen--;
-        if (flen == 0) {
-          mode = 0; unlink(RecName);
-        }
       }
     }
   }
diff --git a/src/sdl-main.c b/src/sdl-main.c
index 892f9e9..8510f2a 100644
--- a/src/sdl-main.c
+++ b/src/sdl-main.c
@@ -66,7 +66,7 @@ static struct option long_options[] = {
   { "leds",       no_argument,       NULL, 'L' },
   { "size",       required_argument, NULL, 's' },
   { "serial-fd",  required_argument, NULL, 'F' },
-  { NULL }
+  { NULL, no_argument, NULL, '\0' }
 };

 static void fail(int code, const char *fmt, ...) {