Restore fix for #7517.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/branches/BRANCH_2_0_X@39090 a592a061-630c-0410-9148-cb99ea01b6c8

src/CutAndPaste.cpp

@@ -647,13 +647,25 @@ void switchBetweenClasses(DocumentClass const * const oldone,
 	DocumentClass const & newtc = *newone;
 
 	// layouts
+	ParIterator it = par_iterator_begin(in);
 	ParIterator end = par_iterator_end(in);
-	for (ParIterator it = par_iterator_begin(in); it != end; ++it) {
+	// for remembering which layouts we've had to add
+	set<docstring> newlayouts;
+	for (; it != end; ++it) {
 		docstring const name = it->layout().name();
 
 		// the pasted text will keep their own layout name. If this layout does
 		// not exist in the new document, it will behave like a standard layout.
-		newtc.addLayoutIfNeeded(name);
+		bool const added_one = newtc.addLayoutIfNeeded(name);
+		if (added_one)
+			newlayouts.insert(name);
+
+		if (added_one || newlayouts.find(name) != newlayouts.end()) {
+			// Warn the user.
+			docstring const s = bformat(_("Layout `%1$s' was not found."), name);
+			errorlist.push_back(
+				ErrorItem(_("Layout Not Found"), s, it->id(), 0, it->size()));
+		}
 
 		if (in.usePlainLayout())
 			it->setLayout(newtc.plainLayout());

src/Text.cpp

@@ -357,6 +357,14 @@ void Text::readParToken(Paragraph & par, Lexer & lex,
 		// all unknown layouts such as frame will be added to document class article so that
 		// these layouts can keep their original names.
 		tclass.addLayoutIfNeeded(layoutname);
+		bool const added_one = tclass.addLayoutIfNeeded(layoutname);
+		if (added_one) {
+			// Warn the user.
+			docstring const s = bformat(_("Layout `%1$s' was not found."), layoutname);
+			errorList.push_back(
+				ErrorItem(_("Layout Not Found"), s, par.id(), 0, par.size()));
+		}
+
 		par.setLayout(bp.documentClass()[layoutname]);
 
 		// Test whether the layout is obsolete.

src/TextClass.cpp

@@ -1199,10 +1199,13 @@ bool TextClass::load(string const & path) const
 }
 
 
-void DocumentClass::addLayoutIfNeeded(docstring const & n) const
+bool DocumentClass::addLayoutIfNeeded(docstring const & n) const
 {
-	if (!hasLayout(n))
-		layoutlist_.push_back(createBasicLayout(n, true));
+	if (hasLayout(n))
+		return false;
+
+	layoutlist_.push_back(createBasicLayout(n, true));
+	return true;
 }
 
 

src/TextClass.h

@@ -373,7 +373,8 @@ public:
 	/// a plain inset layout for use as a default
 	static InsetLayout const & plainInsetLayout() { return plain_insetlayout_; }
 	/// add a new layout \c name if it does not exist in layoutlist_
-	void addLayoutIfNeeded(docstring const & name) const;
+	/// \return whether we had to add one.
+	bool addLayoutIfNeeded(docstring const & name) const;
 
 	///////////////////////////////////////////////////////////////////
 	// accessors

status.20x

@@ -83,6 +83,8 @@ What's new
 
 - Fix output of decimally aligned columns in unviewed (on screen) tables.
 
+- Inform user of unknown layouts caused by class change (bug 7571).
+
 - Avoid LaTeX errors if font changing commands are used in the wrong mode
   by assuring to switch to the right mode on export.