[dev] [sselp] [patch] Offset increment

[Virgile Andreani]

Dear suckless developers,

Using sselp on a string longer than BUFSIZ currently leads to a
crash.  The reason is that on line 38 of `sselp.c`, `off` should
not be incremented by the length of a chunk but by `len/4`.
Indeed, incrementing `off` by 1 skips four characters, not one.

Here is the relevant section of the manpage of XGetWindowProperty:

>       N = actual length of the stored property in bytes
>           (even if the format is 16 or 32)
>       I = 4 * long_offset
>       T = N - I
>       L = MINIMUM(T, 4 * long_length)
>       A = N - (I + L)
> 
> The returned value starts at byte index I in the property
> (indexing from zero), and its length in bytes is L.

Hence the patch, replacing `len` with `len/4`.

Sincerely,
Virgile Andreani


diff --git a/sselp.c b/sselp.c
index 362e397..bf7643e 100644
--- a/sselp.c
+++ b/sselp.c
@@ -35,7 +35,7 @@ main(int argc, char *argv[]) {
 				           False, utf8, &type, &fmt, &len, &more, &data);
 			fwrite(data, 1, len, stdout);
 			XFree(data);
-			off += len;
+			off += len/4;
 		}
 		while(more > 0);
 		putchar('\n');