Fix FILE* resource leak in agread() wrapper

[nehaljwani]

Resolves #213

[codecov-commenter]

Codecov Report

Merging #415 (98802cc) into main (3053c66) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #415   +/-   ##
=======================================
  Coverage   80.87%   80.87%           
=======================================
  Files           5        5           
  Lines        1255     1255           
=======================================
  Hits         1015     1015           
  Misses        240      240           

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[rossbar]

Thanks @nehaljwani !

[rossbar]

Ack, I just noticed that the changes here modify the generated graphviz_wrap.c file directly... this means that the changes would be overridden/lost if/when the C code is regenerated w/ SWIG.

In other words, the changes to graphviz_wrap.c should be instead moved to graphviz.i. Unfortunately the mapping from SWIG definition to C-code is not immediately clear to me... @Nagael , any chance there is a quick fix here? IYO is there a straightforward way to modify graphviz.i to result in the changes we see in graphviz_wrap.c here in this diff?

[dschult]

I'm not sure, and I don't have a setup to test this, but it looks like the following might work:

line 18: add the dup() around fd

        $1 = fdopen(dup(fd), mode);

line 94-96: add a line to fclose(arg1);

%exception agread {
  $action
  fclose(arg1);               // added line
  if (!result) {

[rossbar]

Yeah that was my first thought as well... unfortunately the first line is in a templated function, so it affects two wrapped functions - one of which then causes an infinite hang when running the test suite.

[Nagael]

Hi,
I have a proposition, which I described in #432, and you can see it in this commit . It passes all tests on my setup, but I have no Windows system to test.
Good luck !