[newlib-cygwin] strace: Add comment trying to explain confusing code

[Corinna Vinschen <corinna at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=61401f24ef91b8b4321fd250c5942e9ec6ed3076

commit 61401f24ef91b8b4321fd250c5942e9ec6ed3076
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Sat Oct 22 22:39:31 2016 +0200

    strace: Add comment trying to explain confusing code
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/utils/strace.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/winsup/utils/strace.cc b/winsup/utils/strace.cc
index 5d4a23d..eb96a61 100644
--- a/winsup/utils/strace.cc
+++ b/winsup/utils/strace.cc
@@ -472,6 +472,12 @@ handle_output_debug_string (DWORD id, LPVOID p, unsigned mask, FILE *ofile)
 	len = 17;
     }
 
+  /* Note that the following code deliberately points buf 20 bytes into the
+     allocated area.  The subsequent code then overwrites the usecs value
+     given in the application's debug string, which potentially prepends
+     characters to the string.  If that sounds confusing and dangerous, well...
+
+     TODO: This needs a cleanup. */
   char *buf;
   buf = (char *) alloca (len + 85) + 20;