From 43921861b9b14c2b4f5b2cef8e482a43776fc982 Mon Sep 17 00:00:00 2001
From: Thibaut Cuvelier <tcuvelier@lyx.org>
Date: Sun, 8 Oct 2023 21:06:46 +0200
Subject: [PATCH] DocBook: in InsetInfo, ensure that no db:date is inserted
 within a db:date.

---
 autotests/export/docbook/insetinfo.lyx | 11 +++++++++++
 autotests/export/docbook/insetinfo.xml |  3 +++
 src/Paragraph.cpp                      | 11 ++++++-----
 src/insets/InsetInfo.cpp               | 27 ++++++++++++++++++++++----
 4 files changed, 43 insertions(+), 9 deletions(-)

diff --git a/autotests/export/docbook/insetinfo.lyx b/autotests/export/docbook/insetinfo.lyx
index 1ae6c30760..a1b04a54f9 100644
--- a/autotests/export/docbook/insetinfo.lyx
+++ b/autotests/export/docbook/insetinfo.lyx
@@ -91,6 +91,17 @@ Test:
  InsetInfo
 \end_layout
 
+\begin_layout Date
+
+\lang japanese-cjk
+\begin_inset Info
+type  "moddate"
+arg   "long"
+\end_inset
+
+
+\end_layout
+
 \begin_layout Standard
 
 \lang spanish
diff --git a/autotests/export/docbook/insetinfo.xml b/autotests/export/docbook/insetinfo.xml
index 48ba1d802d..dd0dd6630c 100644
--- a/autotests/export/docbook/insetinfo.xml
+++ b/autotests/export/docbook/insetinfo.xml
@@ -2,6 +2,9 @@
 <!-- This DocBook file was created by LyX 2.4.0~RC1.devel
   See https://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>Test: InsetInfo</title>
+<date>2023-10-08</date>
+</info>
 <para>Véase la <emphasis><phrase role="localized">User's Guide</phrase></emphasis> o <emphasis><phrase role="localized">Additional Features</phrase></emphasis> para más detalles.</para>
 </article>
\ No newline at end of file
diff --git a/src/Paragraph.cpp b/src/Paragraph.cpp
index 333aeb8862..5ac03fa474 100644
--- a/src/Paragraph.cpp
+++ b/src/Paragraph.cpp
@@ -3635,11 +3635,11 @@ std::tuple<vector<xml::FontTag>, vector<xml::EndFontTag>> computeDocBookFontSwit
 
 std::tuple<std::vector<docstring>, std::vector<docstring>, std::vector<docstring>>
     Paragraph::simpleDocBookOnePar(Buffer const & buf,
-                                                      OutputParams const & runparams,
-                                                      Font const & outerfont,
-                                                      pos_type initial,
-                                                      bool is_last_par,
-                                                      bool ignore_fonts) const
+                                   OutputParams const & runparams,
+                                   Font const & outerfont,
+                                   pos_type initial,
+                                   bool is_last_par,
+                                   bool ignore_fonts) const
 {
 	// Return values: segregation of the content of this paragraph.
 	std::vector<docstring> prependedParagraphs; // Anything that must be output before the main tag of this paragraph.
@@ -3669,6 +3669,7 @@ std::tuple<std::vector<docstring>, std::vector<docstring>, std::vector<docstring
             }
         }
     }
+	rp.lastid = id();
 
     // State variables for the main loop.
     auto xs = new XMLStream(os); // XMLStream has no copy constructor: to create a new object, the only solution
diff --git a/src/insets/InsetInfo.cpp b/src/insets/InsetInfo.cpp
index 1f50dfef5f..b08eb7b815 100644
--- a/src/insets/InsetInfo.cpp
+++ b/src/insets/InsetInfo.cpp
@@ -1726,9 +1726,20 @@ void InsetInfo::docbook(XMLStream & xs, OutputParams const & rp) const
 			break;
 		}
 
-		xml::openTag(xs, "date", "role=\"" + role + "\"", "inline");
+		// A db:date cannot be nested within a db:date. This case typically happens when the document class defines a
+		// Date layout. In this case, avoid outputting a new db:date. This means that InsetInfo cannot add a role on top
+		// of the previous db:date, hence add it as a comment. (Another solution would be an XML processing instruction,
+		// but this case is not common enough.) Adding the role to the already output tag might have consequences for
+		// some document classes where the layout already has a role or uses the same role for another purpose.
+		const bool isWithinDate = buffer().getParFromID(rp.lastid).top().paragraph().layout().docbooktag() == "date";
+
+		if (!isWithinDate)
+			xml::openTag(xs, "date", "role=\"" + role + "\"", "inline");
+		else
+			xs << XMLStream::ESCAPE_NONE << from_ascii(std::string("<!-- ") + role + " -->");
 		xs << qstring_to_ucs4(parseDate(buffer(), params_).toString(Qt::ISODate));
-		xml::closeTag(xs, "date", "inline");
+		if (!isWithinDate)
+			xml::closeTag(xs, "date", "inline");
 		break;
 	}
 
@@ -1752,9 +1763,17 @@ void InsetInfo::docbook(XMLStream & xs, OutputParams const & rp) const
 		}
 
 		// DocBook has no specific element for time, so use a date.
-		xml::openTag(xs, "date", "(role=\"" + role + "\"", "inline");
+		// See the discussion above (DATE_INFO, MODDATE_INFO, and FIXDATE_INFO) for a discussion about the choices that
+		// have been made.
+		const bool isWithinDate = buffer().getParFromID(rp.lastid).top().paragraph().layout().docbooktag() == "date";
+
+		if (!isWithinDate)
+			xml::openTag(xs, "date", "role=\"" + role + "\"", "inline");
+		else
+			xs << XMLStream::ESCAPE_NONE << from_ascii(std::string("<!-- ") + role + " -->");
 		xs << qstring_to_ucs4(parseTime(buffer(), params_).toString(Qt::ISODate));
-		xml::closeTag(xs, "date", "inline");
+		if (!isWithinDate)
+			xml::closeTag(xs, "date", "inline");
 		break;
 	}