From baf45b3bc99c5c307d0aa52ff83a9a365a054aed Mon Sep 17 00:00:00 2001
From: Shreesh Adiga <16567adigashreesh@gmail.com>
Date: Mon, 9 Nov 2020 19:53:22 +0530
Subject: vo_sixel: Add checks to prevent null pointer dereferencing.

---
 video/out/vo_sixel.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/video/out/vo_sixel.c b/video/out/vo_sixel.c
index cce6a3da9d..5a5564edc1 100644
--- a/video/out/vo_sixel.c
+++ b/video/out/vo_sixel.c
@@ -162,7 +162,10 @@ static void dealloc_dithers_and_buffer(struct vo* vo)
 {
     struct priv* priv = vo->priv;
 
-    talloc_free(priv->buffer);
+    if (priv->buffer) {
+        talloc_free(priv->buffer);
+        priv->buffer = NULL;
+    }
 
     if (priv->dither) {
         sixel_dither_unref(priv->dither);
@@ -296,6 +299,10 @@ static void flip_page(struct vo *vo)
 {
     struct priv* priv = vo->priv;
 
+    // Make sure that image and dither are valid before drawing
+    if (priv->buffer == NULL || priv->dither == NULL)
+        return;
+
     // Go to the offset row and column, then display the image
     printf(ESC_GOTOXY, priv->top, priv->left);
     sixel_encode(priv->buffer, priv->width, priv->height,
-- 
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