[newlib-cygwin/main] Cygwin: regex: fix freeing g->charjump in low memory condition

[Corinna Vinschen <corinna@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=e914374383a72810bb5d20ad8428843d70df50e1

commit e914374383a72810bb5d20ad8428843d70df50e1
Author:     Corinna Vinschen <corinna@vinschen.de>
AuthorDate: Thu Mar 16 21:52:48 2023 +0100
Commit:     Corinna Vinschen <corinna@vinschen.de>
CommitDate: Mon Mar 20 12:56:17 2023 +0100

    Cygwin: regex: fix freeing g->charjump in low memory condition
    
    computejumps() moves g->charjump to a position relativ to the value of
    CHAR_MIN.  As such, g->charjump doesn't necessarily point to the address
    actually allocated.  While regfree() takes that into account, the low
    memory handling in regcomp_internal() doesn't.  Fix that by free'ing
    the actually allocated address, as in regfree().
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/regex/regcomp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/cygwin/regex/regcomp.c b/winsup/cygwin/regex/regcomp.c
index 59da896a90a1..418e24a90ad2 100644
--- a/winsup/cygwin/regex/regcomp.c
+++ b/winsup/cygwin/regex/regcomp.c
@@ -336,7 +336,7 @@ regcomp_internal(regex_t * __restrict preg,
 		computejumps(p, g);
 		computematchjumps(p, g);
 		if(g->matchjump == NULL && g->charjump != NULL) {
-			free(g->charjump);
+			free(&g->charjump[CHAR_MIN]);
 			g->charjump = NULL;
 		}
 	}