[LyX/2.3.x] Fix problem with synchronous export.

[Richard Kimberly Heck]

commit ffeac12a86bc54db5fdf5659f9300a47e1b2eabb
Author: Richard Kimberly Heck <rikih...@lyx.org>
Date:   Sat Apr 21 19:48:59 2018 -0400

    Fix problem with synchronous export.
    
    It surprises me a bit that the code is different in this case
    from the case when EXPORT_in_THREAD is not set. I should check
    to see if there's a problem in the other case, too.
    
    (cherry picked from commit 0fc50a26371b9cbaf2cd73c5e377c86bf7fdb215)
---
 src/frontends/qt4/GuiView.cpp |   19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/frontends/qt4/GuiView.cpp b/src/frontends/qt4/GuiView.cpp
index af594cb..0eb48cf 100644
--- a/src/frontends/qt4/GuiView.cpp
+++ b/src/frontends/qt4/GuiView.cpp
@@ -3616,12 +3616,9 @@ bool GuiView::GuiViewPrivate::asyncBufferProcessing(
                // We are asynchronous, so we don't know here anything about 
the success
                return true;
        } else {
-#endif
-               // this will be run unconditionally in case EXPORT_in_THREAD
-               // is not defined.
                Buffer::ExportStatus status;
                if (syncFunc) {
-                       status = (used_buffer->*syncFunc)(format, true);
+                       status = (used_buffer->*syncFunc)(format, false);
                } else if (previewFunc) {
                        status = (used_buffer->*previewFunc)(format);
                } else
@@ -3630,9 +3627,19 @@ bool GuiView::GuiViewPrivate::asyncBufferProcessing(
                (void) asyncFunc;
                return (status == Buffer::ExportSuccess
                                || status == Buffer::PreviewSuccess);
-#if EXPORT_in_THREAD
-       // the end of the else clause in that case.
        }
+#else
+       Buffer::ExportStatus status;
+       if (syncFunc) {
+               status = (used_buffer->*syncFunc)(format, true);
+       } else if (previewFunc) {
+               status = (used_buffer->*previewFunc)(format);
+       } else
+               return false;
+       handleExportStatus(gv_, status, format);
+       (void) asyncFunc;
+       return (status == Buffer::ExportSuccess
+                       || status == Buffer::PreviewSuccess);
 #endif
 }