2 files changed, 44 insertions, 8 deletions

diff --git a/src/include/gnunet_configuration_lib.h b/src/include/gnunet_configuration_lib.h
index 77d6d5552..0c87a537d 100644
--- a/src/include/gnunet_configuration_lib.h
+++ b/src/include/gnunet_configuration_lib.h
@@ -154,6 +154,7 @@ int
 GNUNET_CONFIGURATION_write (struct GNUNET_CONFIGURATION_Handle *cfg,
                             const char *filename);
 
+
 /**
  * Write only configuration entries that have been changed to configuration file
  * @param cfgDefault default configuration
@@ -167,6 +168,21 @@ GNUNET_CONFIGURATION_write_diffs (const struct GNUNET_CONFIGURATION_Handle
                                   const struct GNUNET_CONFIGURATION_Handle
                                   *cfgNew, const char *filename);
 
+
+/**
+ * Compute configuration with only entries that have been changed
+ *
+ * @param cfgDefault original configuration
+ * @param cfgNew new configuration
+ * @return configuration with only the differences, never NULL
+ */
+struct GNUNET_CONFIGURATION_Handle *
+GNUNET_CONFIGURATION_get_diff (const struct GNUNET_CONFIGURATION_Handle
+                               *cfgDefault,
+                               const struct GNUNET_CONFIGURATION_Handle
+                               *cfgNew);
+
+
 /**
  * Test if there are configuration options that were
  * changed since the last save.
diff --git a/src/util/configuration.c b/src/util/configuration.c
index f07f61a94..72fe0e7d0 100644
--- a/src/util/configuration.c
+++ b/src/util/configuration.c
@@ -736,8 +736,8 @@ findEntry (const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section,
  * @param value value to copy (of the default conf.)
  */
 static void
-compareEntries (void *cls, const char *section, const char *option,
-                const char *value)
+compare_entries (void *cls, const char *section, const char *option,
+                 const char *value)
 {
   struct DiffHandle *dh = cls;
   struct ConfigEntry *entNew;
@@ -750,6 +750,28 @@ compareEntries (void *cls, const char *section, const char *option,
 
 
 /**
+ * Compute configuration with only entries that have been changed
+ *
+ * @param cfgDefault original configuration
+ * @param cfgNew new configuration
+ * @return configuration with only the differences, never NULL
+ */
+struct GNUNET_CONFIGURATION_Handle *
+GNUNET_CONFIGURATION_get_diff (const struct GNUNET_CONFIGURATION_Handle
+                               *cfgDefault,
+                               const struct GNUNET_CONFIGURATION_Handle
+                               *cfgNew)
+{
+  struct DiffHandle diffHandle;
+
+  diffHandle.cfgDiff = GNUNET_CONFIGURATION_create ();
+  diffHandle.cfgDefault = cfgDefault;
+  GNUNET_CONFIGURATION_iterate (cfgNew, &compare_entries, &diffHandle);
+  return diffHandle.cfgDiff;
+}
+
+
+/**
  * Write only configuration entries that have been changed to configuration file
  * @param cfgDefault default configuration
  * @param cfgNew new configuration
@@ -763,13 +785,11 @@ GNUNET_CONFIGURATION_write_diffs (const struct GNUNET_CONFIGURATION_Handle
                                   *cfgNew, const char *filename)
 {
   int ret;
-  struct DiffHandle diffHandle;
+  struct GNUNET_CONFIGURATION_Handle *diff;
 
-  diffHandle.cfgDiff = GNUNET_CONFIGURATION_create ();
-  diffHandle.cfgDefault = cfgDefault;
-  GNUNET_CONFIGURATION_iterate (cfgNew, compareEntries, &diffHandle);
-  ret = GNUNET_CONFIGURATION_write (diffHandle.cfgDiff, filename);
-  GNUNET_CONFIGURATION_destroy (diffHandle.cfgDiff);
+  diff = GNUNET_CONFIGURATION_get_diff (cfgDefault, cfgNew);
+  ret = GNUNET_CONFIGURATION_write (diff, filename);
+  GNUNET_CONFIGURATION_destroy (diff);
   return ret;
 }