From de09fda5dcef16bf50663f7ffb56074e6ad20b5a Mon Sep 17 00:00:00 2001
From: Ondrej Zajicek <santiago@crfreenet.org>
Date: Thu, 5 Oct 2023 14:26:22 +0200
Subject: [PATCH] Filter: Fix scope handling in for loops

Changes in scope implementation broke scope handling in for loops.
The term in for loops is supposed to be parsed in the parent scope.
---
 filter/config.Y  |  5 ++++-
 filter/test.conf | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/filter/config.Y b/filter/config.Y
index 3cd8e3e4..f3ed2dc5 100644
--- a/filter/config.Y
+++ b/filter/config.Y
@@ -20,6 +20,7 @@ static inline u32 pair_a(u32 p) { return p >> 16; }
 static inline u32 pair_b(u32 p) { return p & 0xFFFF; }
 
 static struct symbol *this_function;
+static struct sym_scope *this_for_scope;
 
 static struct f_method_scope {
   struct f_inst *object;
@@ -993,7 +994,9 @@ cmd:
      new_config->current_scope->slots += 2;
    } for_var IN
    /* Parse term in the parent scope */
-   { new_config->current_scope->active = 0; } term { new_config->current_scope->active = 1; }
+   { this_for_scope = new_config->current_scope; new_config->current_scope = this_for_scope->next; }
+   term
+   { new_config->current_scope = this_for_scope; this_for_scope = NULL; }
    DO cmd {
      cf_pop_block_scope(new_config);
      $$ = f_for_cycle($3, $6, $9);
diff --git a/filter/test.conf b/filter/test.conf
index 22b4984a..f9289189 100644
--- a/filter/test.conf
+++ b/filter/test.conf
@@ -1938,6 +1938,63 @@ bt_test_suite(t_if_else, "Testing if-else statement");
 
 
 
+/*
+ * 	Test for-in statement
+ * 	---------------------
+ */
+
+function t_for_in()
+{
+	bgppath p = +empty+.prepend(5).prepend(4).prepend(3).prepend(2).prepend(1);
+	bgppath q = +empty+.prepend(30).prepend(20).prepend(10);
+	int a;
+
+	# basic for loop
+	a = 0;
+	for int i in p do {
+		a = 2 * a + i;
+	}
+	bt_assert(a = 57);
+
+	# basic for loop, no braces
+	a = 0;
+	for int i in p do a = 2 * a + i;
+	bt_assert(a = 57);
+
+	# for loop with empty body
+	a = 0;
+	for int i in p do { }
+	bt_assert(a = 0);
+
+	# for loop over empty path
+	a = 0;
+	for int i in +empty+ do a = 1;
+	bt_assert(a = 0);
+
+	# for loop with var name shadowing
+	a = 0;
+	for int p in p do {
+		a = 2 * a + p;
+	}
+	bt_assert(a = 57);
+
+	# nested for loops
+	a = 0;
+	int n = 1;
+	for int i in p do {
+		for int j in q do {
+			a = a + i * j * n;
+			n = n + 1;
+		}
+	}
+	bt_assert(a = 9300);
+}
+
+bt_test_suite(t_for_in, "Testing for-in statement");
+
+
+
+
 /*
  *	Unused functions -- testing only parsing
  *	----------------------------------------