Fails to Compile Against Graphviz 13.x

[bassmadrigal]

Graphviz 13.0, released in June, had the following listed in its changelog:

• Breaking: gvRenderData takes its length parameter as a size_t *. The GVJ_t fields output_data_allocated and output_data_position have type size_t.

When graphviz was updated to 13.x in my distro's repo, it broke libmediainfo when compiled with graphviz support, which is a package I maintain for that repo. When trying to compile against the newer graphviz, the error is:

../../../Source/MediaInfo/Export/Export_Graph.cpp:160:60: error: cannot convert ‘unsigned int*’ to ‘size_t*’ {aka ‘long unsigned int*’}
  160 |         gvRenderData(Context, Graph, "svg:cairo", &Buffer, &Size);
      |                                                            ^~~~~
      |                                                            |
      |                                                            unsigned int*
In file included from ../../../Source/MediaInfo/Export/Export_Graph.cpp:35:
/usr/include/graphviz/gvc.h:99:49: note:   initializing argument 5 of ‘int gvRenderData(GVC_t*, graph_t*, const char*, char**, size_t*)’
   99 |                          char **result, size_t *length);
      |                                         ~~~~~~~~^~~~~~
../../../Source/MediaInfo/Export/Export_Graph.cpp:162:54: error: cannot convert ‘unsigned int*’ to ‘size_t*’ {aka ‘long unsigned int*’}
  162 |         gvRenderData(Context, Graph, "svg", &Buffer, &Size);
      |                                                      ^~~~~
      |                                                      |
      |                                                      unsigned int*
In file included from ../../../Source/MediaInfo/Export/Export_Graph.cpp:35:
/usr/include/graphviz/gvc.h:99:49: note:   initializing argument 5 of ‘int gvRenderData(GVC_t*, graph_t*, const char*, char**, size_t*)’
   99 |                          char **result, size_t *length);
      |                                         ~~~~~~~~^~~~~~

We are able to fix this locally with the following sed command:

sed -i 's|unsigned int|size_t|' Source/MediaInfo/Export/Export_Graph*

However, this is not backwards compatible with graphviz 12.x and earlier, so it would seem the code would need some sort of if/then statement to determine the graphviz version and use the correct parameters, but that is beyond my programming expertise.