From c2f2c4343e635a6b8c0f10daa94d5cefde59dfed Mon Sep 17 00:00:00 2001
From: Ander Juaristi <address@hidden>
Date: Tue, 24 May 2016 11:14:38 +0200
Subject: [PATCH] Correct HSTS debug message

 * src/main.c (save_hsts): save the in-memory HSTS database to a file
   only if something changed.
 * src/hsts.c (struct hsts_store): new field 'changed'.
   (hsts_store_entry): update field 'changed' accordingly.
   (hsts_store_has_changed): new function.
 * src/hsts.h (hsts_store_has_changed): new function.
---
 src/hsts.c | 17 ++++++++++++++++-
 src/hsts.h |  1 +
 src/main.c |  8 +++++---
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/src/hsts.c b/src/hsts.c
index d5e0bee..1337a2a 100644
--- a/src/hsts.c
+++ b/src/hsts.c
@@ -53,6 +53,7 @@ as that of the covered work.  */
 struct hsts_store {
   struct hash_table *table;
   time_t last_mtime;
+  bool changed;
 };
 
 struct hsts_kh {
@@ -423,7 +424,10 @@ hsts_store_entry (hsts_store_t store,
       if (entry && match == CONGRUENT_MATCH)
         {
           if (max_age == 0)
-            hsts_remove_entry (store, kh);
+            {
+              hsts_remove_entry (store, kh);
+              store->changed = true;
+            }
           else if (max_age > 0)
             {
               if (entry->max_age != max_age ||
@@ -436,6 +440,8 @@ hsts_store_entry (hsts_store_t store,
                     entry->created = t;
                   entry->max_age = max_age;
                   entry->include_subdomains = include_subdomains;
+
+                  store->changed = true;
                 }
             }
           /* we ignore negative max_ages */
@@ -450,6 +456,8 @@ hsts_store_entry (hsts_store_t store,
              happen we got a non-existent entry with max_age == 0.
           */
           result = hsts_add_entry (store, host, port, max_age, include_subdomains);
+          if (result)
+            store->changed = true;
         }
       /* we ignore new entries with max_age == 0 */
       xfree (kh->host);
@@ -470,6 +478,7 @@ hsts_store_open (const char *filename)
   store = xnew0 (struct hsts_store);
   store->table = hash_table_new (0, hsts_hash_func, hsts_cmp_func);
   store->last_mtime = 0;
+  store->changed = false;
 
   if (file_exists_p (filename))
     {
@@ -531,6 +540,12 @@ hsts_store_save (hsts_store_t store, const char *filename)
     }
 }
 
+bool
+hsts_store_has_changed (hsts_store_t store)
+{
+  return (store ? store->changed : false);
+}
+
 void
 hsts_store_close (hsts_store_t store)
 {
diff --git a/src/hsts.h b/src/hsts.h
index 9a7043d..6e5bbc8 100644
--- a/src/hsts.h
+++ b/src/hsts.h
@@ -43,6 +43,7 @@ hsts_store_t hsts_store_open (const char *);
 
 void hsts_store_save (hsts_store_t, const char *);
 void hsts_store_close (hsts_store_t);
+bool hsts_store_has_changed (hsts_store_t);
 
 bool hsts_store_entry (hsts_store_t,
                        enum url_scheme, const char *, int,
diff --git a/src/main.c b/src/main.c
index ed050a5..e7d5c66 100644
--- a/src/main.c
+++ b/src/main.c
@@ -204,10 +204,12 @@ save_hsts (void)
     {
       char *filename = get_hsts_database ();
 
-      if (filename)
-        DEBUGP (("Saving HSTS entries to %s\n", filename));
+      if (filename && hsts_store_has_changed (hsts_store))
+        {
+          DEBUGP (("Saving HSTS entries to %s\n", filename));
+          hsts_store_save (hsts_store, filename);
+        }
 
-      hsts_store_save (hsts_store, filename);
       hsts_store_close (hsts_store);
 
       xfree (filename);
-- 
2.1.4