From 9ba76e6c40738f9bd0d45d4cdb00a9842d47feec Mon Sep 17 00:00:00 2001
From: Enrico Forestieri <forenr@lyx.org>
Date: Sun, 23 Oct 2016 18:04:13 +0200
Subject: [PATCH] On export, mark the start of the first paragraph

No newline is written after \begin{document}, such that
the afterParbreak method would return false. This misleads
the code that outputs a display math in an ulem command
to emit a newline command instead of \noindent, causing
latex errors. This occurs only if the math is at the very
start of a document, without anything before it.
---
 src/Buffer.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Buffer.cpp b/src/Buffer.cpp
index 67d4b3dc38..df3ae9fb35 100644
--- a/src/Buffer.cpp
+++ b/src/Buffer.cpp
@@ -1891,6 +1891,10 @@ void Buffer::writeLaTeXSource(otexstream & os,
 		os.texrow().start(TexRow::beginDocument());
 		os << "\\begin{document}\n";
 
+		// mark the start of a new paragraph by simulating a newline,
+		// so that os.afterParbreak() returns true at document start
+		os.lastChar('\n');
+
 		// output the parent macros
 		MacroSet::iterator it = parentMacros.begin();
 		MacroSet::iterator end = parentMacros.end();