cgraph: also flush C++ iostreams in exit wrapper

This exit wrapper works around an issue where processes running under MinGW can
exit with unbuffered data remaining in their stdout and stderr internal buffers
without being flushed. The C stdio and C++ iostreams implementations can have
separate buffers. Thus when using this wrapper in C++ code in combination with
C++ iostreams (e.g. cmd/mingle/minglemain.cpp) we need to additionally flush the
C++ buffers as well.

Gitlab: #2178

diff --git a/lib/cgraph/exit.h b/lib/cgraph/exit.h
index 650951b28ac91c4558aefa0f6c34e4af7564b422..e9fd3b9d7da597c97fb8dd15dc0d2b8106455af8 100644 (file)
--- a/lib/cgraph/exit.h
+++ b/lib/cgraph/exit.h
@@ -4,6 +4,8 @@
 #include <stdlib.h>
 
 #ifdef __cplusplus
+#include <iostream>
+
 extern "C" {
 #endif
 
@@ -21,6 +23,10 @@ static inline NORETURN void graphviz_exit(int status) {
   // workaround for https://gitlab.com/graphviz/graphviz/-/issues/2178
   fflush(stdout);
   fflush(stderr);
+#ifdef __cplusplus
+  std::cout.flush();
+  std::cerr.flush();
+#endif
 #endif
   exit(status);
 }