Rob Hooft <rob@hooft.net>:
Description of fcntl(): Added description of what can go wrong.
diff --git a/Doc/lib/libfcntl.tex b/Doc/lib/libfcntl.tex
index ea17665..bf4f375 100644
--- a/Doc/lib/libfcntl.tex
+++ b/Doc/lib/libfcntl.tex
@@ -30,8 +30,14 @@
structure, e.g.\ created by \function{struct.pack()}. The binary
data is copied to a buffer whose address is passed to the C
\cfunction{fcntl()} call. The return value after a successful call
- is the contents of the buffer, converted to a string object. In
- case the \cfunction{fcntl()} fails, an \exception{IOError} is
+ is the contents of the buffer, converted to a string object. The length
+ of the returned string will be the same as the length of the \var{arg}
+ argument. This is limited to 1024 bytes. If the information returned
+ in the buffer by the operating system is larger than 1024 bytes,
+ this is most likely to result in a segmentation violation or a more
+ subtle data corruption.
+
+ If the \cfunction{fcntl()} fails, an \exception{IOError} is
raised.
\end{funcdesc}