From e071ac7b12260b4dcbc80f4c864706de29a6d3c9 Mon Sep 17 00:00:00 2001
From: Bruce Hill <bruce@bruce-hill.com>
Date: Mon, 2 May 2022 17:23:02 -0400
Subject: Bugfix for left recursion

---
 match.c                      | 2 ++
 tests/29-left-recursion3.in  | 1 +
 tests/29-left-recursion3.out | 1 +
 tests/29-left-recursion3.sh  | 2 ++
 4 files changed, 6 insertions(+)
 create mode 100644 tests/29-left-recursion3.in
 create mode 100644 tests/29-left-recursion3.out
 create mode 100644 tests/29-left-recursion3.sh

diff --git a/match.c b/match.c
index 2252fc3..8231fc0 100644
--- a/match.c
+++ b/match.c
@@ -667,7 +667,9 @@ static match_t *match(match_ctx_t *ctx, const char *str, pat_t *pat)
             while (1) {
                 const char *prev = m->end;
                 rec_op.args.leftrec.match = m;
+                ctx2.cache = &(cache_t){0};
                 match_t *m2 = match(&ctx2, str, ref);
+                cache_destroy(&ctx2);
                 if (!m2) break;
                 if (m2->end <= prev) {
                     recycle_match(&m2);
diff --git a/tests/29-left-recursion3.in b/tests/29-left-recursion3.in
new file mode 100644
index 0000000..0830ff2
--- /dev/null
+++ b/tests/29-left-recursion3.in
@@ -0,0 +1 @@
+f!!!
diff --git a/tests/29-left-recursion3.out b/tests/29-left-recursion3.out
new file mode 100644
index 0000000..8ca1cbc
--- /dev/null
+++ b/tests/29-left-recursion3.out
@@ -0,0 +1 @@
+{f!!!}
diff --git a/tests/29-left-recursion3.sh b/tests/29-left-recursion3.sh
new file mode 100644
index 0000000..7de7379
--- /dev/null
+++ b/tests/29-left-recursion3.sh
@@ -0,0 +1,2 @@
+# Left recursion has some tricky edge cases like this:
+bp -p 'shout: phrase `!; phrase: shout / id; phrase => "{@0}"'
-- 
cgit v1.2.3