gh-101955: Fix SystemError in possesive quantifier with alternative and group (GH-111362)

Co-authored-by: <wjssz@users.noreply.github.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/Modules/_sre/sre_lib.h b/Modules/_sre/sre_lib.h
index 0c93f51..af4bfc5 100644
--- a/Modules/_sre/sre_lib.h
+++ b/Modules/_sre/sre_lib.h
@@ -1306,6 +1306,17 @@ dispatch:
                pointer */
             state->ptr = ptr;
 
+            /* Set state->repeat to non-NULL */
+            ctx->u.rep = repeat_pool_malloc(state);
+            if (!ctx->u.rep) {
+                RETURN_ERROR(SRE_ERROR_MEMORY);
+            }
+            ctx->u.rep->count = -1;
+            ctx->u.rep->pattern = NULL;
+            ctx->u.rep->prev = state->repeat;
+            ctx->u.rep->last_ptr = NULL;
+            state->repeat = ctx->u.rep;
+
             /* Initialize Count to 0 */
             ctx->count = 0;
 
@@ -1320,6 +1331,9 @@ dispatch:
                 }
                 else {
                     state->ptr = ptr;
+                    /* Restore state->repeat */
+                    state->repeat = ctx->u.rep->prev;
+                    repeat_pool_free(state, ctx->u.rep);
                     RETURN_FAILURE;
                 }
             }
@@ -1392,6 +1406,10 @@ dispatch:
                 }
             }
 
+            /* Restore state->repeat */
+            state->repeat = ctx->u.rep->prev;
+            repeat_pool_free(state, ctx->u.rep);
+
             /* Evaluate Tail */
             /* Jump to end of pattern indicated by skip, and then skip
                the SUCCESS op code that follows it. */