Store local environment in frame (not terminal) parameters.

* src/callproc.c (child_setup, getenv_internal, Fgetenv_internal):
  Store the local environment in a frame (not terminal) parameter.
  Update doc strings.
  (syms_of_callproc): Update doc strings.
  (Qenvironment): Moved to frame.c. 

* lisp/env.el (read-envvar-name, setenv, getenv, environment): Use frame
  parameters to store the local environment, not terminal parameters.

* server.el (server-process-filter): Store the local environment in a
  frame (not terminal) parameter.  Do not try to decode environment
  strings.

* lisp/frame.el (make-frame): Set up the 'environment frame parameter,
  when needed.

* src/frame.c (Qenvironment): Move here from callproc.c.
  (Fdelete_frame): Don't allow other frames to refer to a deleted frame
  in their 'environment parameter.
  (Fframe_with_environment): New function.
  (syms_of_frame): Defsubr it.  Initialize and staticpro Qenvironment.

* frame.h (Qenvironment): Declare.
* lisp.h (Fframe_with_environment): EXFUN it.

git-archimport-id: lorentey@elte.hu--2004/emacs--multi-tty--0--patch-467

4 files changed, 94 insertions, 38 deletions

diff --git a/src/callproc.c b/src/callproc.c
index ee702fef8c7..715178f8fb2 100644
--- a/src/callproc.c
+++ b/src/callproc.c
@@ -119,7 +119,6 @@ Lisp_Object Vprocess_environment;
 #ifdef DOS_NT
 Lisp_Object Qbuffer_file_type;
 #endif /* DOS_NT */
-Lisp_Object Qenvironment;
 
 /* True iff we are about to fork off a synchronous process or if we
    are waiting for it.  */
@@ -1319,8 +1318,8 @@ child_setup (in, out, err, new_argv, set_pgrp, current_dir)
 
     if (!NILP (Vlocal_environment_variables))
       {
-        local = get_terminal_param (FRAME_DEVICE (XFRAME (selected_frame)),
-                                    Qenvironment);
+        local = get_frame_param (XFRAME (Fframe_with_environment (selected_frame)),
+                                 Qenvironment);
         if (EQ (Vlocal_environment_variables, Qt)
             && !NILP (local))
           environment = local;
@@ -1356,7 +1355,7 @@ child_setup (in, out, err, new_argv, set_pgrp, current_dir)
       new_env = add_env (env, new_env, egetenv (SDATA (XCAR (tem))));
 
     /* The rest of the environment (either Vglobal_environment or the
-       'environment terminal parameter).  */
+       'environment frame parameter).  */
     for (tem = environment;
 	 CONSP (tem) && STRINGP (XCAR (tem));
 	 tem = XCDR (tem))
@@ -1488,12 +1487,12 @@ relocate_fd (fd, minfd)
 }
 
 static int
-getenv_internal (var, varlen, value, valuelen, terminal)
+getenv_internal (var, varlen, value, valuelen, frame)
      char *var;
      int varlen;
      char **value;
      int *valuelen;
-     Lisp_Object terminal;
+     Lisp_Object frame;
 {
   Lisp_Object scan;
   Lisp_Object environment = Vglobal_environment;
@@ -1528,17 +1527,19 @@ getenv_internal (var, varlen, value, valuelen, terminal)
     }
 
   /* Find the environment in which to search the variable. */
-  if (!NILP (terminal))
+  if (!NILP (frame))
     {
-      Lisp_Object local = get_terminal_param (get_device (terminal, 1), Qenvironment);
+      CHECK_FRAME (frame);
+      frame = Fframe_with_environment (frame);
+      Lisp_Object local = get_frame_param (XFRAME (frame), Qenvironment);
       /* Use Vglobal_environment if there is no local environment.  */
       if (!NILP (local))
         environment = local;
     }
   else if (!NILP (Vlocal_environment_variables)) 
     {
-      Lisp_Object local = get_terminal_param (FRAME_DEVICE (XFRAME (selected_frame)),
-                                              Qenvironment);
+      Lisp_Object local = get_frame_param (XFRAME (Fframe_with_environment (selected_frame)),
+                                           Qenvironment);
       if (EQ (Vlocal_environment_variables, Qt)
           && !NILP (local))
         environment = local;
@@ -1594,25 +1595,23 @@ DEFUN ("getenv-internal", Fgetenv_internal, Sgetenv_internal, 1, 2, 0,
 VARIABLE should be a string.  Value is nil if VARIABLE is undefined in
 the environment.  Otherwise, value is a string.
 
-If optional parameter TERMINAL is non-nil, then it should be a
-terminal id or a frame.  If the specified terminal device has its own
-set of environment variables, this function will look up VARIABLE in
-it.
+If optional parameter FRAME is non-nil, then it should be a frame.  If
+that frame has its own set of environment variables, this function
+will look up VARIABLE in there.
 
 Otherwise, this function searches `process-environment' for VARIABLE.
 If it was not found there, then it continues the search in either
 `global-environment' or the local environment list of the current
-terminal device, depending on the value of
-`local-environment-variables'.  */)
-     (variable, terminal)
-     Lisp_Object variable, terminal;
+frame, depending on the value of `local-environment-variables'.  */)
+     (variable, frame)
+     Lisp_Object variable, frame;
 {
   char *value;
   int valuelen;
 
   CHECK_STRING (variable);
   if (getenv_internal (SDATA (variable), SBYTES (variable),
-		       &value, &valuelen, terminal))
+		       &value, &valuelen, frame))
     return make_string (value, valuelen);
   else
     return Qnil;
@@ -1842,11 +1841,10 @@ Each element should be a string of the form ENVVARNAME=VALUE.
 The environment which Emacs inherits is placed in this variable when
 Emacs starts.
 
-Some terminal devices may have their own local list of environment
-variables in their 'environment parameter, which may override this
-global list; see `local-environment-variables'.  See
-`process-environment' for a way to modify an environment variable on
-all terminals.
+Some frames may have their own local list of environment variables in
+their 'environment parameter, which may override this global list; see
+`local-environment-variables'.  See `process-environment' for a way to
+modify an environment variable on all frames.
 
 If multiple entries define the same variable, the first one always
 takes precedence.
@@ -1860,12 +1858,12 @@ See `setenv' and `getenv'.  */);
 Each element should be a string of the form ENVVARNAME=VALUE.
 
 Entries in this list take precedence to those in `global-environment'
-or the terminal environment.  (See `local-environment-variables' for
-an explanation of the terminal-local environment.)  Therefore,
-let-binding `process-environment' is an easy way to temporarily change
-the value of an environment variable, irrespective of where it comes
-from.  To use `process-environment' to remove an environment variable,
-include only its name in the list, without "=VALUE".
+or the frame-local environment.  (See `local-environment-variables'.)
+Therefore, let-binding `process-environment' is an easy way to
+temporarily change the value of an environment variable, irrespective
+of where it comes from.  To use `process-environment' to remove an
+environment variable, include only its name in the list, without
+"=VALUE".
 
 This variable is set to nil when Emacs starts.
 
@@ -1886,21 +1884,18 @@ See `setenv' and `getenv'.  */);
   defsubr (&Scall_process_region);
 
   DEFVAR_LISP ("local-environment-variables", &Vlocal_environment_variables,
-               doc: /* 	Enable or disable terminal-local environment variables.
+               doc: /* 	Enable or disable frame-local environment variables.
 If set to t, `getenv', `setenv' and subprocess creation functions use
-the local environment of the terminal device of the selected frame,
-ignoring `global-environment'.
+the local environment of the selected frame, ignoring
+`global-environment'.
 
 If set to nil, Emacs uses `global-environment' and ignores the
-terminal environment.
+frame-local environment.
 
 Otherwise, `local-environment-variables' should be a list of variable
-names (represented by Lisp strings) to look up in the terminal's
+names (represented by Lisp strings) to look up in the frame's
 environment.  The rest will come from `global-environment'.  */);
   Vlocal_environment_variables = Qnil;
-
-  Qenvironment = intern ("environment");
-  staticpro (&Qenvironment);
 }
 
 /* arch-tag: 769b8045-1df7-4d2b-8968-e3fb49017f95
diff --git a/src/frame.c b/src/frame.c
index c3140628cec..f0657975402 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -111,6 +111,7 @@ Lisp_Object Qbuffer_predicate, Qbuffer_list, Qburied_buffer_list;
 Lisp_Object Qtty_color_mode;
 Lisp_Object Qtty, Qtty_type;
 Lisp_Object Qwindow_system;
+Lisp_Object Qenvironment;
 
 Lisp_Object Qfullscreen, Qfullwidth, Qfullheight, Qfullboth;
 
@@ -1473,6 +1474,24 @@ The functions are run with one arg, the frame to be deleted.  */)
   if (EQ (f->minibuffer_window, echo_area_window))
     echo_area_window = sf->minibuffer_window;
 
+  /* Don't allow other frames to refer to a deleted frame in their
+     'environment parameter.  */
+  {
+    Lisp_Object tail, frame1;
+    Lisp_Object env = get_frame_param (XFRAME (frame), Qenvironment);
+    FOR_EACH_FRAME (tail, frame1)
+      {
+        if (EQ (frame, frame1) || !FRAME_LIVE_P (XFRAME (frame1)))
+          continue;
+        if (EQ (frame, get_frame_param (XFRAME (frame1), Qenvironment)))
+          {
+            store_frame_param (XFRAME (frame1), Qenvironment, env);
+            if (!FRAMEP (env))
+              env = frame1;
+          }
+      }
+  }
+  
   /* Clear any X selections for this frame.  */
 #ifdef HAVE_X_WINDOWS
   if (FRAME_X_P (f))
@@ -2577,6 +2596,43 @@ enabled such bindings for that variable with `make-variable-frame-local'.  */)
 
   return unbind_to (count, Qnil);
 }
+
+DEFUN ("frame-with-environment", Fframe_with_environment, Sframe_with_environment, 0, 1, 0,
+       doc: /* Return the frame that has the environment variable list for FRAME.
+
+The frame-local environment variable list is normally shared between
+frames that were created in the same Emacsclient session.  The
+environment list is stored in a single frame's 'environment parameter;
+the other frames' 'environment parameter is set to this frame.  This
+function follows to chain of 'environment references to reach the
+frame that stores the actual local environment list, and returns that
+frame.  */)
+     (frame)
+     Lisp_Object frame;
+{
+  Lisp_Object hare, tortoise;
+
+  if (NILP (frame))
+    frame = selected_frame;
+  CHECK_FRAME (frame);
+
+  hare = tortoise = get_frame_param (XFRAME (frame), Qenvironment);
+  while (!NILP (hare) && FRAMEP (hare))
+    {
+      frame = hare;
+      hare = get_frame_param (XFRAME (hare), Qenvironment);
+      if (NILP (hare) || !FRAMEP (hare))
+        break;
+      frame = hare;
+      hare = get_frame_param (XFRAME (hare), Qenvironment);
+      tortoise = get_frame_param (XFRAME (tortoise), Qenvironment);
+      if (EQ (hare, tortoise))
+        error ("Cyclic frame-local environment indirection");
+    }
+
+  return frame;
+}
+
 
 DEFUN ("frame-char-height", Fframe_char_height, Sframe_char_height,
        0, 1, 0,
@@ -4232,6 +4288,8 @@ syms_of_frame ()
   staticpro (&Qtty_type);
   Qwindow_system = intern ("window-system");
   staticpro (&Qwindow_system);
+  Qenvironment = intern ("environment");
+  staticpro (&Qenvironment);
   
   Qface_set_after_frame_default = intern ("face-set-after-frame-default");
   staticpro (&Qface_set_after_frame_default);
@@ -4416,6 +4474,7 @@ This variable is local to the current terminal and cannot be buffer-local.  */);
   defsubr (&Sframe_parameters);
   defsubr (&Sframe_parameter);
   defsubr (&Smodify_frame_parameters);
+  defsubr (&Sframe_with_environment);
   defsubr (&Sframe_char_height);
   defsubr (&Sframe_char_width);
   defsubr (&Sframe_pixel_height);
diff --git a/src/frame.h b/src/frame.h
index c63b0bec464..6c54c328923 100644
--- a/src/frame.h
+++ b/src/frame.h
@@ -781,6 +781,7 @@ typedef struct frame *FRAME_PTR;
 extern Lisp_Object Qframep, Qframe_live_p;
 extern Lisp_Object Qtty, Qtty_type;
 extern Lisp_Object Qdevice, Qdisplay_live_p;
+extern Lisp_Object Qenvironment;
 
 extern struct frame *last_nonminibuf_frame;
 
diff --git a/src/lisp.h b/src/lisp.h
index 4b71cd67e98..0aa2d7cb510 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2998,6 +2998,7 @@ EXFUN (Fvisible_frame_list, 0);
 EXFUN (Fframe_parameter, 2);
 EXFUN (Fframe_parameters, 1);
 EXFUN (Fmodify_frame_parameters, 2);
+EXFUN (Fframe_with_environment, 1);
 EXFUN (Fset_frame_height, 3);
 EXFUN (Fset_frame_width, 3);
 EXFUN (Fset_frame_size, 3);