json: Flush standard file descriptors before calling hooks

This ensures messages are displayed in the correct order.

1 files changed, 8 insertions, 0 deletions

diff --git a/apt-private/private-json-hooks.cc b/apt-private/private-json-hooks.cc
index 7991a7d77..6bf70b1c6 100644
--- a/apt-private/private-json-hooks.cc
+++ b/apt-private/private-json-hooks.cc
@@ -11,6 +11,7 @@
 #include <apt-pkg/macros.h>
 #include <apt-pkg/strutl.h>
 #include <apt-private/private-json-hooks.h>
+#include <apt-private/private-output.h>
 
 #include <iomanip>
 #include <ostream>
@@ -335,6 +336,13 @@ bool RunJsonHook(std::string const &option, std::string const &method, const cha
       return true;
    Opts = Opts->Child;
 
+   // Flush output before calling hooks
+   std::clog.flush();
+   std::cerr.flush();
+   std::cout.flush();
+   c2out.flush();
+   c1out.flush();
+
    sighandler_t old_sigpipe = signal(SIGPIPE, SIG_IGN);
    sighandler_t old_sigint = signal(SIGINT, SIG_IGN);
    sighandler_t old_sigquit = signal(SIGQUIT, SIG_IGN);