Clarify what happens with duplicates in process-environment.

diff --git a/lispref/os.texi b/lispref/os.texi
index 6c4a86e3bbecb6b8b3db671b7ede5207d0154c44..d6a58910f40b87c600b98af35b8fe9d04ff55cb1 100644 (file)
--- a/lispref/os.texi
+++ b/lispref/os.texi
@@ -738,6 +738,10 @@ process-environment
     "HOME=/user/lewis")
 @end group
 @end smallexample
+
+If @code{process-environment} contains ``duplicate'' elements that
+specify the same environment variable, the first of these elements
+specifies the variable, and the other ``duplicates'' are ignored.
 @end defvar
 
 @defvar path-separator