From a655ef69a864696569c36ee080923e579d3f1e67 Mon Sep 17 00:00:00 2001
From: Juergen Spitzmueller <spitz@lyx.org>
Date: Sun, 11 Feb 2018 09:50:38 +0100
Subject: [PATCH] Disable BUFFER_EXPORT and BUFFER_EXPORT_AS while buffer is
 processed

I am rather irritated we didn't do this already, since synchronous runs
with BUFFER_VIEW or BUFFER_UPDATE leads to all sorts of problems,
including crashes.

Fixes the crash in #8338 (but not the bug itself).

(cherry picked from commit 1437ae3f9cf78ffd5c639cb4e70a0b1fba9f600e)
---
 src/frontends/qt4/GuiView.cpp | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/frontends/qt4/GuiView.cpp b/src/frontends/qt4/GuiView.cpp
index c587460297..e511cd6cf7 100644
--- a/src/frontends/qt4/GuiView.cpp
+++ b/src/frontends/qt4/GuiView.cpp
@@ -1913,8 +1913,22 @@ bool GuiView::getStatus(FuncRequest const & cmd, FuncStatus & flag)
 		enable = doc_buffer && doc_buffer->notifiesExternalModification();
 		break;
 
-	case LFUN_BUFFER_WRITE_AS:
+	case LFUN_BUFFER_EXPORT: {
+		if (!doc_buffer || d.processing_thread_watcher_.isRunning()) {
+			enable = false;
+			break;
+		}
+		return doc_buffer->getStatus(cmd, flag);
+		break;
+	}
+
 	case LFUN_BUFFER_EXPORT_AS:
+		if (!doc_buffer || d.processing_thread_watcher_.isRunning()) {
+			enable = false;
+			break;
+		}
+		// fall through
+	case LFUN_BUFFER_WRITE_AS:
 		enable = doc_buffer != 0;
 		break;