Re: frame-environment

[Juanma Barranquero]

On Sun, Jan 18, 2009 at 02:52, Stefan Monnier <address@hidden> wrote:

> An entry of the form "VAR" instead of "VAR=VAL".  Such an entry means
> "remove VAR from the environment", IIRC.

Is that standard terminology? I've never heard it.

> This is not the "frame environment" (which is the `environment'
> frame-parameter).

Sorry, I should've said "it only uses the frame parameter to look for
one variable, DISPLAY".

The docstring needs a patch like the attached one, which more
accurately reflects what Fgetenv_internal does. I say "like" because
that docstring still doesn't explain the special case where

  if ((variable is "DISPLAY")
      && (ENV is not a list)
      && ("DISPLAY" not found in `process-environment')
      {
          if (ENV is a frame)
              return `display' parameter of ENV;
          else if (ENV is nil)
              return `display' parameter of selected frame;
          else
              error;
      }

    Juanma


Index: src/callproc.c
===================================================================
RCS file: /cvsroot/emacs/emacs/src/callproc.c,v
retrieving revision 1.243
diff -u -2 -r1.243 callproc.c
--- src/callproc.c      8 Jan 2009 03:15:26 -0000       1.243
+++ src/callproc.c      18 Jan 2009 02:30:41 -0000
@@ -1391,13 +1391,9 @@
 the environment.  Otherwise, value is a string.

-This function searches `process-environment' for VARIABLE.  If it is
-not found there, then it continues the search in the environment list
-of the selected frame.
+This function searches `process-environment' for VARIABLE.

 If optional parameter ENV is a list, then search this list instead of
-`process-environment', and return t when encountering a negative entry.
+`process-environment', and return t when encountering a negative entry
+\(an entry for a variable with no value).  */)
-
-If it is a frame, then this function will ignore `process-environment' and
-will simply look up the variable in that frame's environment.  */)
      (variable, env)
      Lisp_Object variable, env;