[LyX/master] DocBook: allow empty paragraphs before the <info> section.

[Thibaut Cuvelier]

commit c6937cece975ddfbe6b30f1cc85f3aa891d07dad
Author: Thibaut Cuvelier <tcuvelier at lyx.org>
Date:   Sun Aug 2 16:52:33 2020 +0200

    DocBook: allow empty paragraphs before the <info> section.
---
 .../docbook/bibliography_precooked_aastex.xml      |   17 ++++++++++++++
 src/output_docbook.cpp                             |   23 ++++++++++++++++++-
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/autotests/export/docbook/bibliography_precooked_aastex.xml b/autotests/export/docbook/bibliography_precooked_aastex.xml
index 89b1714..37dada8 100644
--- a/autotests/export/docbook/bibliography_precooked_aastex.xml
+++ b/autotests/export/docbook/bibliography_precooked_aastex.xml
@@ -3,6 +3,23 @@
   See http://www.lyx.org/ for more information -->
 <article xml:lang="en_US" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:xi="http://www.w3.org/2001/XInclude" version="5.2">
 <info>
+<title>Collapsed Cores in Globular Clusters,  Gauge-Boson Couplings, and AASTeX Examples</title>
+<author><personname>S. Djorgovski and Ivan R. King</personname></author>
+<author><affiliation>Astronomy Department, University of California, Berkeley, CA 94720</affiliation></author>
+<author><affiliation role="alternate">Visiting Astronomer Cerro Tololo Inter-American Observatory.CTIO is operated by AURA Inc. under contract to the National Science Foundation.</affiliation></author>
+<author><affiliation role="alternate">Society of Fellows, Harvard University.</affiliation></author>
+<author><affiliation role="alternate">present address: Center for Astrophysics60 Garden Street, Cambridge, MA 02138</affiliation></author>
+<author><personname>C. D. Biemesderfer</personname></author>
+<author><affiliation>National Optical Astronomy Observatories, Tucson, AZ 85719</affiliation></author>
+<author><affiliation role="alternate">Visiting Programmer, Space Telescope Science Institute</affiliation></author>
+<author><affiliation role="alternate">Patron, Alonso's Bar and Grill</affiliation></author>
+<author><email>aastex-help at aas.org</email></author>
+<author><personname>R. J. Hanisch</personname></author>
+<author><affiliation>Space Telescope Science Institute, Baltimore, MD 21218</affiliation></author>
+<author><affiliation role="alternate">Patron, Alonso's Bar and Grill</affiliation></author>
+<abstract>
+<para>This is a preliminary report on surface photometry of the major fraction of known globular clusters, to see which of them show the signs of a collapsed core. We also explore some diversionary mathematics and recreational tables. </para>
+</abstract>
 </info>
 <section>
 <title>Introduction</title>
diff --git a/src/output_docbook.cpp b/src/output_docbook.cpp
index 5e15edc..2199239 100644
--- a/src/output_docbook.cpp
+++ b/src/output_docbook.cpp
@@ -764,15 +764,34 @@ DocBookDocumentSectioning hasDocumentSectioning(ParagraphList const &paragraphs,
 }
 
 
-DocBookInfoTag getParagraphsWithInfo(ParagraphList const &paragraphs, pit_type const bpit, pit_type const epit) {
+bool hasOnlyNotes(Paragraph const & par)
+{
+	for (int i = 0; i < par.size(); ++i)
+		if (!par.isInset(i) || !dynamic_cast<InsetNote *>(par.insetList().get(i)))
+			return false;
+	return true;
+}
+
+
+DocBookInfoTag getParagraphsWithInfo(ParagraphList const &paragraphs, pit_type bpit, pit_type const epit) {
 	set<pit_type> shouldBeInInfo;
 	set<pit_type> mustBeInInfo;
 
+	// Find the first non empty paragraph by mutating bpit.
+	while (bpit < epit) {
+		Paragraph const &par = paragraphs[bpit];
+		if (par.empty() || hasOnlyNotes(par))
+			bpit += 1;
+		else
+			break;
+	}
+
+	// Find the last info-like paragraph.
 	pit_type cpit = bpit;
 	while (cpit < epit) {
 		// Skip paragraphs only containing one note.
 		Paragraph const &par = paragraphs[cpit];
-		if (par.size() == 1 && dynamic_cast<InsetNote*>(paragraphs[cpit].insetList().get(0))) {
+		if (hasOnlyNotes(par)) {
 			cpit += 1;
 			continue;
 		}