; Improve documentation of 'with-environment-variables'

* lisp/env.el (with-environment-variables):
* doc/lispref/os.texi (System Environment): Improve the
documentation of 'with-environment-variables'.

2 files changed, 8 insertions, 5 deletions

diff --git a/doc/lispref/os.texi b/doc/lispref/os.texi
index a34c01c81aa..e3297b1be7c 100644
--- a/doc/lispref/os.texi
+++ b/doc/lispref/os.texi
@@ -1043,9 +1043,12 @@ if it removed @var{variable} from the environment.
 @end deffn
 
 @defmac with-environment-variables variables body@dots{}
-This macro sets the environment variables in @var{variables}
+This macro sets the environment variables according to @var{variables}
 temporarily when executing @var{body}.  The previous values are
-restored when the form finishes.
+restored when the form finishes.  The argument @var{variables} should
+be a list of pairs of strings of the form
+@w{@code{(@var{var} @var{value})}}, where @var{var} is the name of the
+environment variable and @var{value} is that variable's value.
 
 @lisp
 (with-environment-variables (("LANG" "C")
diff --git a/lisp/env.el b/lisp/env.el
index 31a728c0e56..2f7cd9d3dbb 100644
--- a/lisp/env.el
+++ b/lisp/env.el
@@ -221,9 +221,9 @@ in the environment list of the selected frame."
 ;;;###autoload
 (defmacro with-environment-variables (variables &rest body)
   "Set VARIABLES in the environent and execute BODY.
-VARIABLES is a list of variable settings where first element
-should be the name of the variable and the second element should
-be the value.
+VARIABLES is a list of variable settings of the form (VAR VALUE),
+where VAR is the name of the variable (a string) and VALUE
+is its value (also a string).
 
 The previous values will be be restored upon exit."
   (declare (indent 1) (debug (sexp body)))