From 9de4d53cf850e0fca625ce9d80c12bea5b2a5ab9 Mon Sep 17 00:00:00 2001
From: Zoltan Herczeg <hzmester@freemail.hu>
Date: Thu, 7 Dec 2023 09:03:24 +0000
Subject: [PATCH] Fix backreferences with unset backref and non-greedy
 iterators in JIT

---
 src/pcre2_jit_compile.c | 3 ++-
 src/pcre2_jit_test.c    | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/pcre2_jit_compile.c b/src/pcre2_jit_compile.c
index 0f445e1..e1daa1e 100644
--- a/src/pcre2_jit_compile.c
+++ b/src/pcre2_jit_compile.c
@@ -9653,7 +9653,8 @@ else
   {
   if (ref)
     {
-    add_jump(compiler, &backtrack->topbacktracks, CMP(SLJIT_EQUAL, TMP1, 0, SLJIT_MEM1(SLJIT_SP), OVECTOR(1)));
+    if (!common->unset_backref)
+      add_jump(compiler, &backtrack->topbacktracks, CMP(SLJIT_EQUAL, TMP1, 0, SLJIT_MEM1(SLJIT_SP), OVECTOR(1)));
     zerolength = CMP(SLJIT_EQUAL, TMP1, 0, SLJIT_MEM1(SLJIT_SP), OVECTOR(offset + 1));
     }
   else
diff --git a/src/pcre2_jit_test.c b/src/pcre2_jit_test.c
index 0974d19..9b63c8e 100644
--- a/src/pcre2_jit_test.c
+++ b/src/pcre2_jit_test.c
@@ -596,6 +596,7 @@ static struct regression_test_case regression_test_cases[] = {
 	{ CMU | PCRE2_DUPNAMES, A, 0, 0, "(?:(?<A>AA)|(?<A>BB))\\k<A>{0,3}?M", "aaaaaabbbbbbaabbbbbbbbbbm" },
 	{ CMU | PCRE2_DUPNAMES, A, 0, 0, "(?:(?<A>AA)|(?<A>BB))\\k<A>{2,3}?", "aaaabbbbaaaabbbbbbbbbb" },
 	{ MU | PCRE2_MATCH_UNSET_BACKREF, A, 0, 0, "(a)|\\1+c", "xxc" },
+	{ MU | PCRE2_MATCH_UNSET_BACKREF, A, 0, 0, "\\1+?()", "" },
 
 	/* Assertions. */
 	{ MU, A, 0, 0, "(?=xx|yy|zz)\\w{4}", "abczzdefg" },
-- 
2.33.0