Patch #1669331: clarify shutil.copyfileobj() behavior wrt. file position.
diff --git a/Doc/lib/libshutil.tex b/Doc/lib/libshutil.tex
index ab2a0c1..2359dea 100644
--- a/Doc/lib/libshutil.tex
+++ b/Doc/lib/libshutil.tex
@@ -34,7 +34,9 @@
is the buffer size. In particular, a negative \var{length} value
means to copy the data without looping over the source data in
chunks; by default the data is read in chunks to avoid uncontrolled
- memory consumption.
+ memory consumption. Note that if the current file position of the
+ \var{fsrc} object is not 0, only the contents from the current file
+ position to the end of the file will be copied.
\end{funcdesc}
\begin{funcdesc}{copymode}{src, dst}