Tweak VG_(expand_file_name), as per Josef's suggestions.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@7204 a5019735-40e9-0310-863c-91ae7b9d1cf9
diff --git a/include/pub_tool_options.h b/include/pub_tool_options.h
index c03920b..7ecac77 100644
--- a/include/pub_tool_options.h
+++ b/include/pub_tool_options.h
@@ -130,6 +130,9 @@
      isn't set, we abort.  If the "{QUAL}" part is malformed, we abort.
    - "%%" is replaced with "%".
    Anything else after '%' causes an abort.
+   If the format specifies a relative file name, it's put in the program's
+   initial working directory.  If it specifies an absolute file name (ie.
+   starts with '/') then it is put there.
 */
 extern Char* VG_(expand_file_name)(Char* option_name, Char* format);