allow '$' as action prefix instead of '%'; backward compatibility is preserved

libraries/librewrite/map.c

@@ -51,7 +51,7 @@ rewrite_map_parse(
 	 * Go to the end of the map invocation (the right closing brace)
 	 */
 	for ( p = string, cnt = 1; p[ 0 ] != '\0' && cnt > 0; p++ ) {
-		if ( p[ 0 ] == REWRITE_SUBMATCH_ESCAPE ) {
+		if ( IS_REWRITE_SUBMATCH_ESCAPE( p[ 0 ] ) ) {
 			/*
 			 * '%' marks the beginning of a new map
 			 */

libraries/librewrite/rewrite-int.h

@@ -55,7 +55,10 @@
  */
 /* the '\' conflicts with slapd.conf parsing */
 /* #define REWRITE_SUBMATCH_ESCAPE			'\\' */
-#define REWRITE_SUBMATCH_ESCAPE                 '%'
+#define REWRITE_SUBMATCH_ESCAPE_ORIG		'%'
+#define REWRITE_SUBMATCH_ESCAPE			'$'
+#define IS_REWRITE_SUBMATCH_ESCAPE(c) \
+	((c) == REWRITE_SUBMATCH_ESCAPE || (c) == REWRITE_SUBMATCH_ESCAPE_ORIG)
 
 /*
  * REGEX flags

libraries/librewrite/subst.c

@@ -55,11 +55,11 @@ rewrite_subst_compile(
 		/*
 		 * Keep only single escapes '%'
 		 */
-		if ( p[ 0 ] != REWRITE_SUBMATCH_ESCAPE ) {
+		if (  !IS_REWRITE_SUBMATCH_ESCAPE( p[ 0 ] ) ) {
 			continue;
 		} 
 
-		if ( p[ 1 ] == REWRITE_SUBMATCH_ESCAPE ) {
+		if (  IS_REWRITE_SUBMATCH_ESCAPE( p[ 1 ] ) ) {
 			/* Pull &p[1] over p, including the trailing '\0' */
 			AC_MEMCPY((char *)p, &p[ 1 ], strlen( p ) );
 			continue;