From c9a46a91fe43e847c0a90dcdf5fce2e4abbdf667 Mon Sep 17 00:00:00 2001
From: Nick Wellnhofer <wellnhofer@aevum.de>
Date: Wed, 20 Dec 2023 20:11:09 +0100
Subject: [PATCH] io: Rework initialization

---
 include/private/io.h |  3 +++
 threads.c            |  2 ++
 xmlIO.c              | 29 +++++++++++++++++++++--------
 3 files changed, 26 insertions(+), 8 deletions(-)

diff --git a/include/private/io.h b/include/private/io.h
index ca2c8e7e..b6de9822 100644
--- a/include/private/io.h
+++ b/include/private/io.h
@@ -5,6 +5,9 @@
 #include <libxml/tree.h>
 #include <libxml/xmlversion.h>
 
+XML_HIDDEN void
+xmlInitIOCallbacks(void);
+
 XML_HIDDEN int
 __xmlIOErr(int domain, int code, const char *extra);
 
diff --git a/threads.c b/threads.c
index 651ce642..e5c14387 100644
--- a/threads.c
+++ b/threads.c
@@ -30,6 +30,7 @@
 #include "private/dict.h"
 #include "private/enc.h"
 #include "private/globals.h"
+#include "private/io.h"
 #include "private/memory.h"
 #include "private/threads.h"
 #include "private/xpath.h"
@@ -590,6 +591,7 @@ xmlInitParser(void) {
 #if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED)
         xmlInitXPathInternal();
 #endif
+        xmlInitIOCallbacks();
 
         xmlParserInnerInitialized = 1;
     }
diff --git a/xmlIO.c b/xmlIO.c
index 059b2288..e7eea45c 100644
--- a/xmlIO.c
+++ b/xmlIO.c
@@ -90,10 +90,8 @@ xmlIODefaultMatch(const char *filename);
 
 #define MAX_INPUT_CALLBACK 10
 
-static xmlInputCallback xmlInputCallbackTable[MAX_INPUT_CALLBACK] = {
-    { xmlIODefaultMatch, NULL, NULL, NULL }
-};
-static int xmlInputCallbackNr = 1;
+static xmlInputCallback xmlInputCallbackTable[MAX_INPUT_CALLBACK];
+static int xmlInputCallbackNr;
 
 #ifdef LIBXML_OUTPUT_ENABLED
 /*
@@ -108,10 +106,8 @@ typedef struct _xmlOutputCallback {
 
 #define MAX_OUTPUT_CALLBACK 10
 
-static xmlOutputCallback xmlOutputCallbackTable[MAX_OUTPUT_CALLBACK] = {
-    { xmlIODefaultMatch, NULL, NULL, NULL },
-};
-static int xmlOutputCallbackNr = 1;
+static xmlOutputCallback xmlOutputCallbackTable[MAX_OUTPUT_CALLBACK];
+static int xmlOutputCallbackNr;
 #endif /* LIBXML_OUTPUT_ENABLED */
 
 /************************************************************************
@@ -4023,6 +4019,23 @@ xmlNoNetExternalEntityLoader(const char *URL, const char *ID,
  *									*
  ************************************************************************/
 
+/**
+ * xmlInitIOCallbacks:
+ *
+ * Initialize callback tables.
+ */
+void
+xmlInitIOCallbacks(void)
+{
+    xmlInputCallbackNr = 1;
+    xmlInputCallbackTable[0].matchcallback = xmlIODefaultMatch;
+
+#ifdef LIBXML_OUTPUT_ENABLED
+    xmlOutputCallbackNr = 1;
+    xmlOutputCallbackTable[0].matchcallback = xmlIODefaultMatch;
+#endif
+}
+
 /**
  * xmlRegisterInputCallbacks:
  * @matchFunc:  the xmlInputMatchCallback