* edit.c (check_file_access): Use non-blocking open() followed

by fstat() to avoid race conditions.  Don't ask users to
recompile the editor.

edit/ChangeLog

@@ -1,5 +1,9 @@
 2002-12-15  Pavel Roskin  <proski@gnu.org>
 
+	* edit.c (check_file_access): Use non-blocking open() followed
+	by fstat() to avoid race conditions.  Don't ask users to
+	recompile the editor.
+
 	* edit.c (edit_reload): Don't initialize edit->macro_i, because
 	edit_init() takes care of it.
 	* editwidget.c (edit): Likewise.

edit/edit.c

@@ -328,38 +328,34 @@ static int
 check_file_access (WEdit *edit, const char *filename, struct stat *st)
 {
     int file;
-    int flags;
-    int stat_ok = 0;
 
-    /* Try stat first to prevent getting stuck on pipes */
+    /* Try opening an existing file */
-    if (mc_stat ((char *) filename, st) == 0) {
+    file = mc_open (filename, O_NONBLOCK | O_RDONLY | O_BINARY, 0666);
-	stat_ok = 1;
+
+    if (file < 0) {
+	/*
+	 * Try creating the file.  O_EXCL prevents following broken links
+	 * and opening existing files.
+	 */
+	file =
+	    mc_open (filename,
+		     O_NONBLOCK | O_RDONLY | O_BINARY | O_CREAT | O_EXCL,
+		     0666);
+	if (file < 0) {
+	    edit_error_dialog (_("Error"),
+			       get_sys_error (catstrs
+					      (_
+					       (" Cannot open file for reading: "),
+					       filename, " ", 0)));
+	    return 1;
+	} else {
+	    /* New file, delete it if it's not modified or saved */
+	    edit->delete_file = 1;
+	}
     }
 
-    /* Only regular files are allowed */
+    /* Check what we have opened */
-    if (stat_ok && !S_ISREG (st->st_mode)) {
+    if (mc_fstat (file, st) < 0) {
-	edit_error_dialog (_("Error"),
-			   catstrs (_(" Not an ordinary file: "), filename,
-				    " ", 0));
-	return 1;
-    }
-
-    /* Open the file, create it if (and only if!) needed */
-    flags = O_RDONLY | O_CREAT | O_BINARY;
-    if (!stat_ok)
-	flags |= O_EXCL;
-
-    if ((file = mc_open (filename, flags, 0666)) < 0) {
-	edit_error_dialog (_("Error"),
-			   get_sys_error (catstrs
-					  (_
-					   (" Cannot open file for reading: "),
-					   filename, " ", 0)));
-	return 1;
-    }
-
-    /* If the file has just been created, we don't have valid stat yet, so do it now */
-    if (!stat_ok && mc_fstat (file, st) < 0) {
 	mc_close (file);
 	edit_error_dialog (_("Error"),
 			   get_sys_error (catstrs
@@ -368,22 +364,34 @@ check_file_access (WEdit *edit, const char *filename, struct stat *st)
 					   filename, " ", 0)));
 	return 1;
     }
+
+    /* We want to open regular files only */
+    if (!S_ISREG (st->st_mode)) {
+	mc_close (file);
+	edit_error_dialog (_("Error"),
+			   catstrs (_(" Not an ordinary file: "), filename,
+				    " ", 0));
+	return 1;
+    }
+
     mc_close (file);
 
-    /* If it's a new file, delete it if it's not modified or saved */
+    /*
-    if (!stat_ok && st->st_size == 0) {
+     * Don't delete non-empty files.
-	edit->delete_file = 1;
+     * O_EXCL should prevent it, but let's be on the safe side.
+     */
+    if (st->st_size > 0) {
+	edit->delete_file = 0;
     }
 
     if (st->st_size >= SIZE_LIMIT) {
-	/* The file-name is printed after the ':' */
+	mc_close (file);
 	edit_error_dialog (_("Error"),
 			   catstrs (_(" File is too large: "), filename,
-				    _
-				    (" \n Increase edit.h:MAXBUF and recompile the editor. "),
 				    0));
 	return 1;
     }
+
     return 0;
 }