Rewrite redirect handling code with nested lists.

New ll_addh to add items to the head of a nested list (use with care!).

bin/werc.rc

@@ -89,20 +89,16 @@ fn werc_exec_request {
 
     if(~ $#perm_redir_to 1)
         perm_redirect $perm_redir_to
-    p=();
-    for(i in $perm_redir_patterns) {
-        if(~ $#p 0)
-            p=$i
-        if not {
-            # If target is absolute, require patern matches whole string
-            if(~ $i http://* https://)
-                p='^'$p 
-            t=`{ echo $req_path | sed 's!'$p'!'$i'!' }
+    for(l in $perm_redir_patterns) {
+        p=$$l
+        r=$p(1)
+        # If target is absolute, then patern must match whole string
+        if(~ $p(2) http://* https://)
+            r='^'$r 
+        t=`{ echo $req_path | sed 's!'^$r^'!'^$p(2)^'!' } # Malicious danger!
 
-            if(! ~ $"t '' && ! ~ $t $req_path)
-                perm_redirect $t
-            p=() 
-        } 
+        if(! ~ $"t '' $req_path)
+            perm_redirect $t
     }
 
     # Set Page title