(init_cmdargs): Set Vinstallation_directory.

(syms_of_emacs): staticpro it.

1 files changed, 82 insertions, 0 deletions

diff --git a/src/emacs.c b/src/emacs.c
index bd5e175bebe..e7b2f41b0aa 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -63,6 +63,10 @@ Lisp_Object Vinvocation_name;
 /* The directory name from which Emacs was invoked.  */
 Lisp_Object Vinvocation_directory;
 
+/* The directory name in which to find subdirs such as lisp and etc.
+   nil means get them only from PATH_LOADSEARCH.  */
+Lisp_Object Vinstallation_directory;
+
 /* Hook run by `kill-emacs' before it does really anything.  */
 Lisp_Object Vkill_emacs_hook;
 
@@ -179,6 +183,7 @@ init_cmdargs (argc, argv, skip_args)
      int skip_args;
 {
   register int i;
+  Lisp_Object name, dir;
 
   Vinvocation_name = Ffile_name_nondirectory (build_string (argv[0]));
   Vinvocation_directory = Ffile_name_directory (build_string (argv[0]));
@@ -193,6 +198,81 @@ init_cmdargs (argc, argv, skip_args)
         Vinvocation_directory = Ffile_name_directory (found);
     }
 
+  Vinstallation_directory = Qnil;
+
+  if (!NILP (Vinvocation_directory))
+    {
+      dir = Vinvocation_directory;
+      name = Fexpand_file_name (Vinvocation_name, dir);
+      while (1)
+        {
+          Lisp_Object tem, lisp_exists, lib_src_exists;
+          Lisp_Object etc_exists, info_exists;
+
+          /* See if dir contains subdirs for use by Emacs.  */
+          tem = Fexpand_file_name (build_string ("lisp"), dir);
+          lisp_exists = Ffile_exists_p (tem);
+          if (!NILP (lisp_exists))
+            {
+              tem = Fexpand_file_name (build_string ("lib-src"), dir);
+              lib_src_exists = Ffile_exists_p (tem);
+              if (!NILP (lib_src_exists))
+                {
+                  tem = Fexpand_file_name (build_string ("etc"), dir);
+                  etc_exists = Ffile_exists_p (tem);
+                  if (!NILP (etc_exists))
+                    {
+                      tem = Fexpand_file_name (build_string ("info"), dir);
+                      info_exists = Ffile_exists_p (tem);
+                      if (!NILP (info_exists))
+                        {
+                          Vinstallation_directory
+                            = Ffile_name_as_directory (dir);
+                          break;
+                        }
+                    }
+                }
+            }
+
+          /* See if dir's parent contains those subdirs.  */
+          tem = Fexpand_file_name (build_string ("../lisp"), dir);
+          lisp_exists = Ffile_exists_p (tem);
+          if (!NILP (lisp_exists))
+            {
+              tem = Fexpand_file_name (build_string ("../lib-src"), dir);
+              lib_src_exists = Ffile_exists_p (tem);
+              if (!NILP (lib_src_exists))
+                {
+                  tem = Fexpand_file_name (build_string ("../etc"), dir);
+                  etc_exists = Ffile_exists_p (tem);
+                  if (!NILP (etc_exists))
+                    {
+                      tem = Fexpand_file_name (build_string ("../info"), dir);
+                      info_exists = Ffile_exists_p (tem);
+                      if (!NILP (info_exists))
+                        {
+                          tem = Fexpand_file_name (build_string (".."), dir);
+                          Vinstallation_directory
+                            = Ffile_name_as_directory (tem);
+                          break;
+                        }
+                    }
+                }
+            }
+
+          /* If the Emacs executable is actually a link,
+             next try the dir that the link points into.  */
+          tem = Ffile_symlink_p (name);
+          if (!NILP (tem))
+            {
+              name = tem;
+              dir = Ffile_name_directory (name);
+            }
+          else
+            break;
+        }
+    }
+
   Vcommand_line_args = Qnil;
 
   for (i = argc - 1; i >= 0; i--)
@@ -962,6 +1042,8 @@ and only if the Emacs executable is installed with setuid to permit\n\
 it to change priority.  (Emacs sets its uid back to the real uid.)");
   emacs_priority = 0;
 
+  staticpro (&Vinstallation_directory);
+  Vinstallation_directory = Qnil;
   staticpro (&Vinvocation_name);
   Vinvocation_name = Qnil;
   staticpro (&Vinvocation_directory);