- move the string join() function to utils.c since it is used in both cli.c and res_agi.c

- reimplement ast_join to be of linear effieciency instead of quadratic
- remove some useless checks for "if (e)"
- reorder checks for strings starting with '_' to avoid a useless call to ast_join()
- check array bounds when parsing arguments to AGI
(issue #5868)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@7556 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/strings.h

@@ -165,6 +165,7 @@ void ast_copy_string(char *dst, const char *src, size_t size),
 }
 )
 
+
 /*!
   \brief Build a string in a buffer, designed to be called repeatedly
   
@@ -210,6 +211,18 @@ int ast_true(const char *val);
  */
 int ast_false(const char *val);
 
+/*
+  \brief Join an array of strings into a single string.
+  \param s the resulting string buffer
+  \param len the length of the result buffer, s
+  \param w an array of strings to join
+
+  This function will join all of the strings in the array 'w' into a single
+  string.  It will also place a space in the result buffer in between each
+  string from 'w'.
+*/
+void ast_join(char *s, size_t len, char * const w[]);
+
 /* The realloca lets us ast_restrdupa(), but you can't mix any other ast_strdup calls! */
 
 struct ast_realloca {