much better swap logic to support reentrancy and fix assert failure

Commit c74340f9 added backreferences as well as the idea of a ->swap
regex pointer to keep track of the match offsets in case of backtracking.
The problem is that when Perl re-enters the regex engine to handle
utf8::SWASHNEW, the ->swap is not saved/restored/cleared so any capture
from the utf8 (Perl) code could inadvertently modify the regex match
data that caused the utf8 swash to get built.

This change should close out RT #60508

1 files changed, 0 insertions, 2 deletions

diff --git a/regcomp.c b/regcomp.c
index 22c02c82ad..696796b796 100644
--- a/regcomp.c
+++ b/regcomp.c
@@ -9414,7 +9414,6 @@ Perl_pregfree2(pTHX_ REGEXP *rx)
     if (r->saved_copy)
         SvREFCNT_dec(r->saved_copy);
 #endif
-    Safefree(r->swap);
     Safefree(r->offs);
 }
 
@@ -9474,7 +9473,6 @@ Perl_reg_temp_copy (pTHX_ REGEXP *rx)
     ret->saved_copy = NULL;
 #endif
     ret->mother_re = rx;
-    ret->swap = NULL;
     
     return ret_x;
 }