This is because gtkmathview is including C++ files inside an extern "C" block. I've applied the attached patch in Ubuntu, which fixes this. Thanks for considering it for Debian!
-- -mt
Index: gtkmathview-0.8.0/src/widget/gtkmathview_common.h =================================================================== --- gtkmathview-0.8.0.orig/src/widget/gtkmathview_common.h +++ gtkmathview-0.8.0/src/widget/gtkmathview_common.h @@ -22,6 +22,17 @@ #include <gtk/gtkwidget.h> +/* Include these outside the extern "c" bit */ +#if GTKMATHVIEW_USES_CUSTOM_READER +#include "c_customXmlReader.h" +#elif GTKMATHVIEW_USES_LIBXML2_READER +#include <libxml/xmlreader.h> +#elif GTKMATHVIEW_USES_LIBXML2 +#include <libxml/tree.h> +#elif GTKMATHVIEW_USES_GMETADOM +#include <gdome.h> +#endif + #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ @@ -45,23 +56,19 @@ extern "C" { typedef void* GtkMathViewReaderData; #if GTKMATHVIEW_USES_CUSTOM_READER -#include "c_customXmlReader.h" #define GTKMATHVIEW_METHOD_NAME(name) gtk_math_view_##name##__##custom_reader typedef void* GtkMathViewModelId; typedef const char* GtkMathViewModelString; #elif GTKMATHVIEW_USES_LIBXML2_READER -#include <libxml/xmlreader.h> #define GTKMATHVIEW_METHOD_NAME(name) gtk_math_view_##name##__##libxml2_reader typedef void* GtkMathViewModelId; typedef const xmlChar* GtkMathViewModelString; #elif GTKMATHVIEW_USES_LIBXML2 -#include <libxml/tree.h> #define GTKMATHVIEW_METHOD_NAME(name) gtk_math_view_##name##__##libxml2 typedef xmlElement* GtkMathViewModelId; typedef xmlDoc* GtkMathViewModelDocument; typedef const xmlChar* GtkMathViewModelString; #elif GTKMATHVIEW_USES_GMETADOM -#include <gdome.h> #define GTKMATHVIEW_METHOD_NAME(name) gtk_math_view_##name##__##gmetadom typedef GdomeElement* GtkMathViewModelId; typedef GdomeDocument* GtkMathViewModelDocument;