Fix footnote output in tables outside floats and longtable header/footer

Fixes: #808 (sic!), #5869
(cherry picked from commit 3affde3957)

lib/chkconfig.ltx

@@ -315,6 +315,7 @@
 \TestPackage{float}
 \TestPackage{fontspec}
 \TestPackage{footmisc}
+\TestPackage{footnote}
 \TestPackage{forest}
 \TestPackage{framed}
 \TestPackage{geometry}

lib/doc/LaTeXConfig.lyx

@@ -5152,6 +5152,37 @@ here, definitely!
  
 \end_layout
 
+\begin_layout Subsection
+footnote
+\end_layout
+
+\begin_layout Description
+Found: 
+\begin_inset Info
+type  "package"
+arg   "footnote"
+\end_inset
+
+
+\end_layout
+
+\begin_layout Description
+CTAN: 
+\family typewriter
+macros/latex/contrib/footnote/
+\end_layout
+
+\begin_layout Description
+Notes: The package 
+\family sans
+footnote
+\family default
+ is needed by \SpecialChar LyX
+ to allow footnotes in non-floating tables and multi-page
+ table headers and footers.
+ 
+\end_layout
+
 \begin_layout Subsection
 graphicx
 \end_layout

src/LaTeXFeatures.cpp

@@ -974,6 +974,7 @@ char const * simplefeatures[] = {
 	"todonotes",
 	"forest",
 	"varwidth",
+	"footnote",
 };
 
 char const * bibliofeatures[] = {

src/LaTeXFeatures.h

@@ -163,6 +163,10 @@ public:
 	bool inDeletedInset() const { return in_deleted_inset_; }
 	/// are we in a deleted inset?
 	void inDeletedInset(bool const b) { in_deleted_inset_ = b; }
+	/// set savenote environment (footnote package)
+	std::string saveNoteEnv() const { return savenote_env_; }
+	/// return savenote environment
+	void saveNoteEnv(std::string const s) { savenote_env_ = s; }
 	/// Runparams that will be used for exporting this file.
 	OutputParams const & runparams() const { return runparams_; }
 	/// Resolve alternatives like "esint|amsmath|wasysym"
@@ -221,6 +225,8 @@ private:
 	bool in_deleted_inset_;
 	///
 	docstring htmltitle_;
+	///
+	std::string savenote_env_;
 };
 
 

src/insets/InsetFoot.cpp

@@ -17,6 +17,7 @@
 #include "BufferParams.h"
 #include "Counters.h"
 #include "Language.h"
+#include "LaTeXFeatures.h"
 #include "Layout.h"
 #include "OutputParams.h"
 #include "ParIterator.h"
@@ -104,4 +105,18 @@ int InsetFoot::docbook(odocstream & os, OutputParams const & runparams) const
 	return i;
 }
 
+
+void InsetFoot::validate(LaTeXFeatures & features) const
+{
+	if (!features.saveNoteEnv().empty()) {
+		features.require("footnote");
+		features.addPreambleSnippet(
+			from_ascii("\\makesavenoteenv{"
+				   + features.saveNoteEnv()
+				   + "}\n"));
+	}
+
+	InsetText::validate(features);
+}
+
 } // namespace lyx

src/insets/InsetFoot.h

@@ -36,6 +36,8 @@ private:
 	              size_t max_length = INT_MAX) const;
 	///
 	int docbook(odocstream &, OutputParams const &) const;
+	///
+	void validate(LaTeXFeatures & features) const;
 	/// Update the counters of this inset and of its contents
 	void updateBuffer(ParIterator const &, UpdateType);
 	///

src/insets/InsetTabular.cpp

@@ -3424,7 +3424,16 @@ void Tabular::validate(LaTeXFeatures & features) const
 		if (getVAlignment(cell) != LYX_VALIGN_TOP
 		    || !getPWidth(cell).zero())
 			features.require("array");
+		// Tell footnote that we need a savenote
+		// environment in non-long tables or
+		// longtable headers/footers
+		if (!is_long_tabular)
+			features.saveNoteEnv("tabular");
+		else if (!isValidRow(cellRow(cell)))
+			features.saveNoteEnv("longtable");
+
 		cellInset(cell)->validate(features);
+		features.saveNoteEnv(string());
 	}
 }