Implement the $(urlprefixes) built-in function.

* NEWS: Update.
* README: Update.
* configure.ac: Version 2.2.91
* doc/vmod-dbrw.3: Document the use of $(urlprefixes) built-in
* doc/vmod-dbrw.texi: Likewise.
* src/vmod_dbrw.c (parse_flags): Make sure status string is null-terminated.
(do_rewrite): Expand built-in functions in $(). Support urlprefixes.
On debug_level=100, produce detailed trace of expansions.
* src/wordsplit.c: Pull from grecs commit 9097d529.
* src/wordsplit.h: Likewise.
* tests/initdb.at (rewrite): Change the url column.
* tests/rewrite01.at: Use $(urlprefixes) in the SQL templates.
* tests/rewrite02.at: Likewise.
* tests/rewrite03.at: Likewise.
* tests/rewrite04.at: Likewise.
* tests/rewrite05.at: Likewise.
* tests/rewrite06.at: Likewise.

1 files changed, 29 insertions, 2 deletions

diff --git a/NEWS b/NEWS
index 913b0f9..c700564 100644
--- a/NEWS
+++ b/NEWS
@@ -1,9 +1,9 @@
-vmod-dbrw -- history of user-visible changes. 2018-01-30
+vmod-dbrw -- history of user-visible changes. 2018-12-08
 See the end of file for copying conditions.
 
 Please send vmod-dbrw bug reports to <gray@gnu.org>
 
-Version 2.2.90 (Git)
+Version 2.2.91 (Git)
 
 * SQL idle timeout
 
@@ -18,6 +18,33 @@ e.g.:
              {"select dest,pattern,value,flags from rewrite where
                locate(url,'$url') = 1 order by weight asc;"});
 
+* The $() functions in SQL templates
+
+The SQL templates support the use of $() constructs for invoking
+built-in functions. So far one function is implemented:
+
+ $(urlprefixes PATH)
+
+It expands to comma-separated list of properly quoted pathname
+prefixes, constructed from its argument. Optional query part is
+stripped off the argument prior to expansion. For example 
+
+  $(urlprefixes "/local/user/local?a=1")
+
+expands to:
+
+  '/local/user/local','/local/user','/local'
+
+This construct is intended for use in SQL IN conditionals, for
+example:
+
+  SELECT dest,pattern,value,flags
+  FROM rewrite
+  WHERE host='$host'
+    AND url IN ($(urlprefixes $url))
+  ORDER BY length(dest),value,weight DESC
+
+
 	       
 Version 2.2, 2017-08-10