ap_expr related fixes/enhancements:

- implement regex backreferences and make them available for setting 
  envvars in SetEnvIfExpr
- implement nested function calls in %-syntax: %{func1:%{func2:arg}} 
- actually implement evaluation of concatenation operator (oops...)
- Fix <If ... > treating an internal error as success


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1037504 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 26 insertions, 5 deletions

diff --git a/server/util_expr_scan.l b/server/util_expr_scan.l
index 05ff3a116b..79bdbc16f9 100644
--- a/server/util_expr_scan.l
+++ b/server/util_expr_scan.l
@@ -142,14 +142,30 @@
     *str_ptr++ = yytext[1];
 }
 
-<str,vararg>[^\\\n"'%}]+ {
+ /* regexp backref inside string/arg */
+<str,vararg>[$][0-9] {
+    if (str_ptr != str_buf) {
+        /* return what we have so far and scan '$x' again */
+        *str_ptr = '\0';
+        yylval->cpVal = apr_pstrdup(yyextra->pool, str_buf);
+        str_ptr = str_buf;
+        yyless(0);
+        return T_STRING;
+    }
+    else {
+        yylval->num = yytext[1] - '0';
+        return T_REGEX_BACKREF;
+    }
+}
+
+<str,vararg>[^\\\n"'%}$]+ {
     char *cp = yytext;
     while (*cp != '\0')
         *str_ptr++ = *cp++;
 }
 
- /* variable inside string */
-<str>%\{ {
+ /* variable inside string/arg */
+<str,vararg>%\{ {
     if (str_ptr != str_buf) {
         /* return what we have so far and scan '%{' again */
         *str_ptr = '\0';
@@ -164,11 +180,11 @@
     }
 }
 
-<vararg>% {
+<vararg>[%$] {
      *str_ptr++ = yytext[0];
 }
 
-<str>[%}] {
+<str>[%}$] {
      *str_ptr++ = yytext[0];
 }
 
@@ -177,6 +193,11 @@
     return T_VAR_BEGIN;
 }
 
+[$][0-9] {
+    yylval->num = yytext[1] - '0';
+    return T_REGEX_BACKREF;
+}
+
  /*
   * fixed name variable expansion %{XXX} and function call in %{func:arg} syntax
   */