tdf#118373 xmlsecurity: avoid stderr output on libxmlsec version check

Make sure that our normal SAL_WARN() reporting is registered during the
xmlSecCheckVersionExt() invocation, just like it's registered during
other libxmlsec API calls.

Change-Id: Ia19368b55dbae47974f48954f86b50e36d1462ff
Reviewed-on: https://gerrit.libreoffice.org/64550Reviewed-by: Miklos Vajna <vmiklos@collabora.com>
Tested-by: Jenkins

xmlsecurity/source/xmlsec/xmlstreamio.cxx

@@ -22,8 +22,10 @@
  * Implementation of the I/O interfaces based on stream and URI binding
  */
 #include <xmlsec/xmlstreamio.hxx>
+#include <xmlsec/errorcallback.hxx>
 #include <rtl/ustring.hxx>
 #include <rtl/uri.hxx>
+#include <comphelper/scopeguard.hxx>
 
 #include <libxml/uri.h>
 #include <xmlsec-wrapper.h>
@@ -151,6 +153,10 @@ XSECXMLSEC_DLLPUBLIC int xmlEnableStreamInputCallbacks()
         //Notes: all none default callbacks will lose.
         xmlSecIOCleanupCallbacks() ;
 
+        // Make sure that errors are reported via SAL_WARN().
+        setErrorRecorder();
+        comphelper::ScopeGuard g([] { clearErrorRecorder(); });
+
         // Newer xmlsec wants the callback order in the opposite direction.
         if (xmlSecCheckVersionExt(1, 2, 26, xmlSecCheckVersionABICompatible))
         {