#11 Failing to build with libxml 2.14

[papoteur]

With libxml 2.14, I get

gcc -DPACKAGE_NAME=\"lsdvd\" -DPACKAGE_TARNAME=\"lsdvd\" -DPACKAGE_VERSION=\"0.20\" -DPACKAGE_STRING=\"lsdvd\ 0.20\" -DPACKAGE_BUGREPORT=\"\" -DPACKAGE_URL=\"\" -DPACKAGE=\"lsdvd\" -DVERSION=\"0.20\" -I.     -I/usr/include/libxml2 -O2 -g -pipe -Wformat -Werror=format-security -Wp,-U_FORTIFY_SOURCE,-D_FORTIFY_SOURCE=3 -specs=/usr/lib/rpm/redhat/redhat-hardened-cc1 -fstack-protector-strong -m64 -fasynchronous-unwind-tables -fstack-clash-protection -fcf-protection=full -W -Wall -Wcast-align -Wcast-qual -Wpointer-arith -Wreturn-type -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wformat -Werror=format-security -g -c -o lsdvd-oxml.o `test -f 'oxml.c' || echo './'`oxml.c
oxml.c: In function 'ConvertInput':
oxml.c:47:17: warning: 'input' is deprecated [-Wdeprecated-declarations]
   47 |                 ret = handler->input(out, &out_size, (const xmlChar *) in, &temp);
      |                 ^~~
In file included from /usr/include/libxml2/libxml/xmlIO.h:18,
                 from /usr/include/libxml2/libxml/xmlwriter.h:21,
                 from oxml.c:2:
/usr/include/libxml2/libxml/encoding.h:204:7: note: declared here
  204 |     } input XML_DEPRECATED_MEMBER;
      |       ^~~~~
oxml.c:47:23: error: called object is not a function or function pointer
   47 |                 ret = handler->input(out, &out_size, (const xmlChar *) in, &temp);
      |                       ^~~~~~~
make: *** [Makefile:713: lsdvd-oxml.o] Error 1

[Carl Smedstad]

Applied the following patch to fix this in our package for Arch Linux:

From c3cd98688b6f114bc8414a99e0796131b7dd6a43 Mon Sep 17 00:00:00 2001
From: Carl Smedstad <carsme@archlinux.org>
Date: Mon, 1 Dec 2025 21:41:39 +0100
Subject: [PATCH] Fix build with libxml2 2.14+

The handler->input() function pointer was deprecated and changed to a
union in libxml2 2.14. Use the modern xmlBuffer-based API with
xmlCharEncInFunc() instead of directly accessing the handler struct.

Disclaimer: Authored with assistance from Claude Code.
---
 oxml.c | 52 ++++++++++++++++++++++++++--------------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/oxml.c b/oxml.c
index cc59ee5..ea2cc0a 100644
--- a/oxml.c
+++ b/oxml.c
@@ -21,9 +21,9 @@ static xmlChar *
 ConvertInput(const char *in, const char *encoding)
 {
    xmlChar *out;
-   int size;
-   int out_size;
    xmlCharEncodingHandlerPtr handler;
+   xmlBufferPtr inbuf, outbuf;
+   int ret;

    if (in == 0)
        return 0;
@@ -36,34 +36,34 @@ ConvertInput(const char *in, const char *encoding)
        return 0;
    }

-   size = (int) strlen(in) + 1;
-   out_size = size * 4 - 1; // Assume max 4 bytes for each character in UTF-8
-   out = (unsigned char *) xmlMalloc((size_t) out_size);
+   inbuf = xmlBufferCreate();
+   if (inbuf)
+       xmlBufferAdd(inbuf, (const xmlChar *)in, strlen(in));
+   outbuf = xmlBufferCreate();

-   if (out != 0) {
-       int ret;
-       int temp;
-       temp = size - 1;
-       ret = handler->input(out, &out_size, (const xmlChar *) in, &temp);
-       if ((ret < 0) || (temp - size + 1)) {
-           if (ret < 0) {
-               printf("ConvertInput: conversion wasn't successful.\n");
-           } else {
-               printf
-                 ("ConvertInput: conversion wasn't successful. converted: %i octets.\n",
-                  temp);
-           }
-
-           xmlFree(out);
-           out = NULL;
-       } else {
-           out = (unsigned char *) xmlRealloc(out, out_size + 1);
-           out[out_size] = 0;  /*null terminating out */
-       }
-   } else {
+   if (inbuf == NULL || outbuf == NULL) {
        printf("ConvertInput: no mem\n");
+       if (inbuf) xmlBufferFree(inbuf);
+       if (outbuf) xmlBufferFree(outbuf);
+       xmlCharEncCloseFunc(handler);
+       return 0;
    }

+   ret = xmlCharEncInFunc(handler, outbuf, inbuf);
+   if (ret < 0) {
+       printf("ConvertInput: conversion wasn't successful.\n");
+       xmlBufferFree(inbuf);
+       xmlBufferFree(outbuf);
+       xmlCharEncCloseFunc(handler);
+       return 0;
+   }
+
+   out = xmlStrdup(xmlBufferContent(outbuf));
+
+   xmlBufferFree(inbuf);
+   xmlBufferFree(outbuf);
+   xmlCharEncCloseFunc(handler);
+
    return out;
 }

-- 
2.52.0