Fix backreferences with unset backref and non-greedy iterators in JIT

Author: zherczeg

ChangeLog

@@ -189,6 +189,8 @@ in particular k and s.
 
 51. Fix accept and endanchored interaction in JIT.
 
+52. Fix backreferences with unset backref and non-greedy iterators in JIT.
+
 
 Version 10.42 11-December-2022
 ------------------------------

src/pcre2_jit_compile.c

@@ -9653,7 +9653,8 @@ else
   {
   if (ref)
     {
-    add_jump(compiler, &backtrack->own_backtracks, CMP(SLJIT_EQUAL, TMP1, 0, SLJIT_MEM1(SLJIT_SP), OVECTOR(1)));
+    if (!common->unset_backref)
+      add_jump(compiler, &backtrack->own_backtracks, 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

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" },