fix the figsize segfault bug

Cryoris · lava · commit 4ace1ad946e2 · 2019-07-03T13:51:39.000+02:00
plt::figure_size is known to sometimes cause segfaults if called
without a preceding plt::figure
as suggested in the issues this is fixed by calling
detail::_interpreter::get() at the beginning of the function
diff --git a/matplotlibcpp.h b/matplotlibcpp.h
@@ -1116,6 +1116,9 @@ inline bool fignum_exists(long number)
 
 inline void figure_size(size_t w, size_t h)
 {
+    // Make sure interpreter is initialised
+    detail::_interpreter::get();
+
     const size_t dpi = 100;
     PyObject* size = PyTuple_New(2);
     PyTuple_SetItem(size, 0, PyFloat_FromDouble((double)w / dpi));

Original file line number	Diff line number	Diff line change
`@@ -1116,6 +1116,9 @@ inline bool fignum_exists(long number)`
`1116`	`1116`
`1117`	`1117`	`inline void figure_size(size_t w, size_t h)`
`1118`	`1118`	`{`
	`1119`	`+ // Make sure interpreter is initialised`
	`1120`	`+ detail::_interpreter::get();`
	`1121`	`+`
`1119`	`1122`	`const size_t dpi = 100;`
`1120`	`1123`	`PyObject* size = PyTuple_New(2);`
`1121`	`1124`	`PyTuple_SetItem(size, 0, PyFloat_FromDouble((double)w / dpi));`