config: Create ast_variable_find_in_list()

Add
const char *ast_variable_find_in_list(const struct ast_variable *list,
   const char *variable);

ast_variable_find() requires a config category to search whereas
ast_variable_find_in_list() just needs the root list element which is
useful if you don't have a category.

Tested-by: George Joseph

Review: https://reviewboard.asterisk.org/r/4217/
........

Merged revisions 428733 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/13@428734 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/config.h

@@ -311,6 +311,20 @@ const char *ast_variable_retrieve(struct ast_config *config,
  */
 const char *ast_variable_find(const struct ast_category *category, const char *variable);
 
+/*!
+ * \brief Gets a variable from a variable list
+ *
+ * \param list variable list to search
+ * \param variable which variable you wish to get the data for
+ *
+ * \details
+ * Goes through a given variable list and searches for the given variable
+ *
+ * \retval The variable value on success
+ * \retval NULL if unable to find it.
+ */
+const char *ast_variable_find_in_list(const struct ast_variable *list, const char *variable);
+
 /*!
  * \brief Retrieve a category if it exists
  *

main/config.c

@@ -720,9 +720,14 @@ const char *ast_variable_retrieve_filtered(struct ast_config *config,
 
 const char *ast_variable_find(const struct ast_category *category, const char *variable)
 {
-	struct ast_variable *v;
+	return ast_variable_find_in_list(category->root, variable);
+}
+
+const char *ast_variable_find_in_list(const struct ast_variable *list, const char *variable)
+{
+	const struct ast_variable *v;
 
-	for (v = category->root; v; v = v->next) {
+	for (v = list; v; v = v->next) {
 		if (!strcasecmp(variable, v->name)) {
 			return v->value;
 		}