From 44a285a9a29e67872091350448bdb79e5c9435a7 Mon Sep 17 00:00:00 2001
From: ziyangc <chenziyang4@huawei.com>
Date: Fri, 25 Nov 2022 11:35:44 +0800
Subject: [PATCH] Fix heap buffer overflow in function
 yaml_emitter_emit_flow_sequence_item, releated
 issue:https://github.com/yaml/libyaml/issues/258

---
 src/emitter.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/emitter.c b/src/emitter.c
index 609b28a4..3ad29591 100644
--- a/src/emitter.c
+++ b/src/emitter.c
@@ -758,8 +758,14 @@ yaml_emitter_emit_flow_sequence_item(yaml_emitter_t *emitter,
     if (event->type == YAML_SEQUENCE_END_EVENT)
     {
         emitter->flow_level --;
-        emitter->indent = POP(emitter, emitter->indents);
-        if (emitter->canonical && !first) {
+        if (!STACK_EMPTY(emitter, emitter->indents)) {
+	    emitter->indent = POP(emitter, emitter->indents);
+	}
+	else {
+	    emitter->indent = 0; // set to default
+        }
+        
+	if (emitter->canonical && !first) {
             if (!yaml_emitter_write_indicator(emitter, ",", 0, 0, 0))
                 return 0;
             if (!yaml_emitter_write_indent(emitter))