(init_cmdargs): Allow `installation-directory'

to be set if either `lib-src' or `info' are found as its
subdirectories or siblings.

1 files changed, 13 insertions, 2 deletions

diff --git a/src/emacs.c b/src/emacs.c
index fca9faf100e..7349a21698d 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -270,7 +270,14 @@ init_cmdargs (argc, argv, skip_args)
              not including lisp and info.  */
           tem = Fexpand_file_name (build_string ("lib-src"), dir);
           lib_src_exists = Ffile_exists_p (tem);
-          if (!NILP (lib_src_exists))
+
+          /* MSDOS installations frequently remove lib-src, but we still
+             must set installation-directory, or else info won't find
+             its files (it uses the value of installation-directory).  */
+          tem = Fexpand_file_name (build_string ("info"), dir);
+          info_exists = Ffile_exists_p (tem);
+
+          if (!NILP (lib_src_exists) || !NILP (info_exists))
             {
               tem = Fexpand_file_name (build_string ("etc"), dir);
               etc_exists = Ffile_exists_p (tem);
@@ -285,7 +292,11 @@ init_cmdargs (argc, argv, skip_args)
           /* See if dir's parent contains those subdirs.  */
           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 ("../info"), dir);
+          info_exists = Ffile_exists_p (tem);
+
+          if (!NILP (lib_src_exists) || !NILP (info_exists))
             {
               tem = Fexpand_file_name (build_string ("../etc"), dir);
               etc_exists = Ffile_exists_p (tem);