+/*
+ * Internal function supporting the jump list registry code. All the
+ * functions to add, remove and read the list have substantially
+ * similar content, so this is a generalisation of all of them which
+ * transforms the list in the registry by prepending 'add' (if
+ * non-null), removing 'rem' from what's left (if non-null), and
+ * returning the resulting concatenated list of strings in 'out' (if
+ * non-null).
+ */
+static int transform_jumplist_registry
+ (const char *add, const char *rem, char **out)
+{
+ int ret;
+ HKEY pjumplist_key, psettings_tmp;
+ DWORD type;
+ int value_length;
+ char *old_value, *new_value;
+ char *piterator_old, *piterator_new, *piterator_tmp;
+
+ ret = RegCreateKeyEx(HKEY_CURRENT_USER, reg_jumplist_key, 0, NULL,
+ REG_OPTION_NON_VOLATILE, (KEY_READ | KEY_WRITE), NULL,
+ &pjumplist_key, NULL);
+ if (ret != ERROR_SUCCESS) {
+ return JUMPLISTREG_ERROR_KEYOPENCREATE_FAILURE;
+ }
+
+ /* Get current list of saved sessions in the registry. */
+ value_length = 200;
+ old_value = snewn(value_length, char);
+ ret = RegQueryValueEx(pjumplist_key, reg_jumplist_value, NULL, &type,
+ old_value, &value_length);
+ /* When the passed buffer is too small, ERROR_MORE_DATA is
+ * returned and the required size is returned in the length
+ * argument. */
+ if (ret == ERROR_MORE_DATA) {
+ sfree(old_value);
+ old_value = snewn(value_length, char);
+ ret = RegQueryValueEx(pjumplist_key, reg_jumplist_value, NULL, &type,
+ old_value, &value_length);
+ }
+
+ if (ret == ERROR_FILE_NOT_FOUND) {
+ /* Value doesn't exist yet. Start from an empty value. */
+ *old_value = '\0';
+ *(old_value + 1) = '\0';
+ } else if (ret != ERROR_SUCCESS) {
+ /* Some non-recoverable error occurred. */
+ sfree(old_value);
+ RegCloseKey(pjumplist_key);
+ return JUMPLISTREG_ERROR_VALUEREAD_FAILURE;
+ } else if (type != REG_MULTI_SZ) {
+ /* The value present in the registry has the wrong type: we
+ * try to delete it and start from an empty value. */
+ ret = RegDeleteValue(pjumplist_key, reg_jumplist_value);
+ if (ret != ERROR_SUCCESS) {
+ sfree(old_value);
+ RegCloseKey(pjumplist_key);
+ return JUMPLISTREG_ERROR_VALUEREAD_FAILURE;
+ }
+
+ *old_value = '\0';
+ *(old_value + 1) = '\0';
+ }
+
+ /* Check validity of registry data: REG_MULTI_SZ value must end
+ * with \0\0. */
+ piterator_tmp = old_value;
+ while (((piterator_tmp - old_value) < (value_length - 1)) &&
+ !(*piterator_tmp == '\0' && *(piterator_tmp+1) == '\0')) {
+ ++piterator_tmp;
+ }
+
+ if ((piterator_tmp - old_value) >= (value_length-1)) {
+ /* Invalid value. Start from an empty value. */
+ *old_value = '\0';
+ *(old_value + 1) = '\0';
+ }
+
+ /*
+ * Modify the list, if we're modifying.
+ */
+ if (add || rem) {
+ /* Walk through the existing list and construct the new list of
+ * saved sessions. */
+ new_value = snewn(value_length + (add ? strlen(add) + 1 : 0), char);
+ piterator_new = new_value;
+ piterator_old = old_value;
+
+ /* First add the new item to the beginning of the list. */
+ if (add) {
+ strcpy(piterator_new, add);
+ piterator_new += strlen(piterator_new) + 1;
+ }
+ /* Now add the existing list, taking care to leave out the removed
+ * item, if it was already in the existing list. */
+ while (*piterator_old != '\0') {
+ if (!rem || strcmp(piterator_old, rem) != 0) {
+ /* Check if this is a valid session, otherwise don't add. */
+ psettings_tmp = open_settings_r(piterator_old);
+ if (psettings_tmp != NULL) {
+ close_settings_r(psettings_tmp);
+ strcpy(piterator_new, piterator_old);
+ piterator_new += strlen(piterator_new) + 1;
+ }
+ }
+ piterator_old += strlen(piterator_old) + 1;
+ }
+ *piterator_new = '\0';
+ ++piterator_new;
+
+ /* Save the new list to the registry. */
+ ret = RegSetValueEx(pjumplist_key, reg_jumplist_value, 0, REG_MULTI_SZ,
+ new_value, piterator_new - new_value);
+
+ sfree(old_value);
+ old_value = new_value;
+ } else
+ ret = ERROR_SUCCESS;
+
+ /*
+ * Either return or free the result.
+ */
+ if (out)
+ *out = old_value;
+ else
+ sfree(old_value);
+
+ /* Clean up and return. */
+ RegCloseKey(pjumplist_key);
+
+ if (ret != ERROR_SUCCESS) {
+ return JUMPLISTREG_ERROR_VALUEWRITE_FAILURE;
+ } else {
+ return JUMPLISTREG_OK;
+ }
+}
+
+/* Adds a new entry to the jumplist entries in the registry. */
+int add_to_jumplist_registry(const char *item)
+{
+ return transform_jumplist_registry(item, item, NULL);
+}
+
+/* Removes an item from the jumplist entries in the registry. */
+int remove_from_jumplist_registry(const char *item)
+{
+ return transform_jumplist_registry(NULL, item, NULL);
+}
+
+/* Returns the jumplist entries from the registry. Caller must free
+ * the returned pointer. */
+char *get_jumplist_registry_entries (void)
+{
+ char *list_value;
+
+ if (transform_jumplist_registry(NULL,NULL,&list_value) != ERROR_SUCCESS) {
+ list_value = snewn(2, char);
+ *list_value = '\0';
+ *(list_value + 1) = '\0';
+ }
+ return list_value;
+}
+