Write cookies to a temporary file first, to be safe

It may happen that we are running out of space in the middle
of writing the file, and fopen deleted it already.

diff --git a/katze/katze-http-cookies.c b/katze/katze-http-cookies.c
index c66ee66ca7cd27a4708cbe862f27a7d98edec939..c52f788646724e43f51bd91fa088466df411aab5 100644 (file)
--- a/katze/katze-http-cookies.c
+++ b/katze/katze-http-cookies.c
@@ -16,9 +16,13 @@
 #include "katze-http-cookies.h"
 
 #include <stdlib.h>
+#ifdef HAVE_UNISTD_H
+    #include <unistd.h>
+#endif
 #include <glib/gi18n.h>
 #include <libsoup/soup.h>
 #include <gtk/gtk.h>
+#include <glib/gstdio.h>
 
 struct _KatzeHttpCookies
 {
@@ -145,12 +149,12 @@ cookie_jar_load (SoupCookieJar* jar,
    Copyright (C) 2008 Xan Lopez <xan@gnome.org>
    Copyright (C) 2008 Dan Winship <danw@gnome.org>
    Copied from libSoup 2.24, coding style preserved */
-static void
+static gboolean
 write_cookie (FILE *out, SoupCookie *cookie)
 {
        fseek (out, 0, SEEK_END);
 
-       fprintf (out, "%s%s\t%s\t%s\t%s\t%lu\t%s\t%s\n",
+       if (fprintf (out, "%s%s\t%s\t%s\t%s\t%lu\t%s\t%s\n",
                 cookie->http_only ? "#HttpOnly_" : "",
                 cookie->domain,
                 *cookie->domain == '.' ? "TRUE" : "FALSE",
@@ -158,7 +162,9 @@ write_cookie (FILE *out, SoupCookie *cookie)
                 cookie->secure ? "TRUE" : "FALSE",
                 (gulong)soup_date_to_time_t (cookie->expires),
                 cookie->name,
-                cookie->value);
+                cookie->value) < 0)
+            return FALSE;
+        return TRUE;
 }
 
 /* Cookie jar saving to Mozilla format
@@ -170,18 +176,21 @@ delete_cookie (const char *filename, SoupCookie *cookie)
 {
        char *contents = NULL, *line, *p;
        gsize length = 0;
+       gint fn = 0;
        FILE *f;
+       gchar* temporary_filename = NULL;
        SoupCookie *c;
        time_t now = time (NULL);
 
        if (!g_file_get_contents (filename, &contents, &length, NULL))
                return;
 
-       f = fopen (filename, "w");
-       if (!f) {
-               g_free (contents);
-               return;
-       }
+       fn = g_file_open_tmp (NULL, &temporary_filename, NULL);
+       if (fn == -1)
+               goto failed;
+       f = fopen (temporary_filename, "w");
+       if (!f)
+               goto failed;
 
        line = contents;
        for (p = contents; *p; p++) {
@@ -200,12 +209,24 @@ delete_cookie (const char *filename, SoupCookie *cookie)
        c = parse_cookie (line, now);
        if (c) {
                if (!soup_cookie_equal (cookie, c))
-                       write_cookie (f, c);
+                       if (!write_cookie (f, c))
+                               goto failed;
                soup_cookie_free (c);
        }
 
+       if (!fclose (f))
+            goto failed;
+
        g_free (contents);
-       fclose (f);
+        close (fn);
+        g_rename (temporary_filename, filename);
+        g_free (temporary_filename);
+        return;
+failed:
+        g_free (contents);
+        close (fn);
+        g_unlink (temporary_filename);
+        g_free (temporary_filename);
 }
 
 /* Cookie jar saving to Mozilla format