From 9feafbc5c5cce13852062a527d719ecce6b54661 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Sun, 13 Nov 2022 16:56:10 +0100
Subject: [PATCH] io: Check for memory buffer early in xmlParserInputGrow

---
 parserInternals.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/parserInternals.c b/parserInternals.c
index 9dbc8f26..022c728b 100644
--- a/parserInternals.c
+++ b/parserInternals.c
@@ -299,6 +299,9 @@ xmlParserInputGrow(xmlParserInputPtr in, int len) {
     if (in->cur == NULL) return(-1);
     if (in->buf->buffer == NULL) return(-1);
 
+    /* Don't grow memory buffers. */
+    if (in->buf->readcallback == NULL) return(0);
+
     CHECK_BUFFER(in);
 
     indx = in->cur - in->base;
@@ -308,10 +311,7 @@ xmlParserInputGrow(xmlParserInputPtr in, int len) {
 
         return(0);
     }
-    if (in->buf->readcallback != NULL) {
-	ret = xmlParserInputBufferGrow(in->buf, len);
-    } else
-        return(0);
+    ret = xmlParserInputBufferGrow(in->buf, len);
 
     in->base = xmlBufContent(in->buf->buffer);
     in->cur = in->base + indx;