(te-create-terminfo): Use make-temp-file

to create the source file in a safe way.

diff --git a/lisp/terminal.el b/lisp/terminal.el
index 438f16906732d32211b344bebe4927a59f86639d..7d89f3ff824ca51805ba2cbd60b251b00117ffe8 100644 (file)
--- a/lisp/terminal.el
+++ b/lisp/terminal.el
@@ -1264,10 +1264,10 @@ of the terminal-emulator"
 (defun te-create-terminfo ()
   "Create and compile a terminfo entry for the virtual terminal. This is kept
 in the directory specified by `te-terminfo-directory'."
-  (if (and system-uses-terminfo
-          (not (file-exists-p (concat  te-terminfo-directory
-                                       (substring te-terminal-name-prefix 0 1)
-                                       "/" te-terminal-name))))
+  (when (and system-uses-terminfo
+            (not (file-exists-p (concat te-terminfo-directory
+                                        (substring te-terminal-name-prefix 0 1)
+                                        "/" te-terminal-name))))
     (let ( (terminfo
            (concat
             ;; The first newline avoids trouble with ncurses.
@@ -1278,24 +1278,30 @@ in the directory specified by `te-terminfo-directory'."
             "dch=^Pd%p1%'\\s'%+%c, dch1=^Pd!, dl=^P^K%p1%'\\s'%+%c,"
             "dl1=^P^K!, ed=^PC, el=^Pc, home=^P=\\s\\s,"
             "ich=^P_%p1%'\\s'%+%c, ich1=^P_!, il=^P^O%p1%'\\s'%+%c,"
+            ;; The last newline avoids trouble with ncurses.
             "il1=^P^O!, ind=^P\\n, nel=\\n,\n"))
-          ;; The last newline avoids trouble with ncurses.
+          ;; This is the desired name for the source file.
           (file-name (concat te-terminfo-directory te-terminal-name ".tif")) )
       (make-directory te-terminfo-directory t)
-      (save-excursion
-       (set-buffer (create-file-buffer file-name))
-       (insert terminfo)
-       (write-file file-name)
-       (kill-buffer nil)
-       )
-      (let ( (process-environment
-             (cons (concat "TERMINFO="
-                           (directory-file-name te-terminfo-directory))
-                   process-environment)) )
+      (let ((temp-file
+            (make-temp-file (expand-file-name "tif" te-terminfo-directory))))
+       ;; Store the source file under a random temp name.
+       (with-temp-file temp-file
+         (insert terminfo))
+       ;; Rename it to the desired name.
+       ;; We use this roundabout approach
+       ;; to avoid any risk of writing a name that
+       ;; was michievouslyt set up as a symlink.
+       (rename-file temp-file file-name))
+      ;; Now compile that source to make the binary that the
+      ;; programs actually use.
+      (let ((process-environment
+            (cons (concat "TERMINFO="
+                          (directory-file-name te-terminfo-directory))
+                  process-environment)))
        (set-process-sentinel (start-process "tic" nil "tic" file-name)
                              'te-tic-sentinel))))
-    (directory-file-name te-terminfo-directory)
-)
+    (directory-file-name te-terminfo-directory))
 
 (defun te-create-termcap ()
   "Create a termcap entry for the virtual terminal"