Correct stack unwinding inside recursions when seeing (*SKIP).

Fixes #152.
boostorg · Oct 20, 2021 · 354e02f · 354e02f
1 parent 75600e3
commit 354e02f
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/include/boost/regex/v5/perl_matcher_non_recursive.hpp b/include/boost/regex/v5/perl_matcher_non_recursive.hpp
@@ -417,7 +417,8 @@ bool perl_matcher<BidiIterator, Allocator, traits>::match_startmark()
          {
             // Must be unwinding from a COMMIT/SKIP/PRUNE and the independent 
             // sub failed, need to unwind everything else:
-            while(unwind(false));
+            while (m_backup_state->state_id)
+               unwind(false);
             return false;
          }
 #if !defined(BOOST_NO_EXCEPTIONS)

diff --git a/test/regress/test_perl_ex.cpp b/test/regress/test_perl_ex.cpp
@@ -999,6 +999,9 @@ void test_verbs()
    TEST_REGEX_SEARCH("AA+(*SKIP)(B|Z)|C", perl, "AAAC", match_default, make_array(3, 4, -1, -1, -2, -2));
    TEST_REGEX_SEARCH("AA+(*SKIP)(B|Z)|AC", perl, "AAAC", match_default, make_array(-2, -2));
    TEST_REGEX_SEARCH("AA+(*SKIP)B|C", perl, "AAAC", match_default, make_array(3, 4, -2, -2));
+
+   // https://github.com/boostorg/regex/issues/152
+   TEST_REGEX_SEARCH("\\A((\x1f((?1)    )?+)?+(*SKIP) *?(?2)*?)\\z", perl, "\x20\x1f\x1f\x20", match_default, make_array(-2, -2));
 
    TEST_REGEX_SEARCH("^(?:aaa(*THEN)\\w{6}|bbb(*THEN)\\w{5}|ccc(*THEN)\\w{4}|\\w{3})", perl, "aaaxxxxxx", match_default, make_array(0, 9, -2, -2));
    TEST_REGEX_SEARCH("^(?:aaa(*THEN)\\w{6}|bbb(*THEN)\\w{5}|ccc(*THEN)\\w{4}|\\w{3})", perl, "aaa++++++", match_default, make_array(-2, -2));