From 61d68d05bd0f2172ab9406f23dc2640e6b9ac56b Mon Sep 17 00:00:00 2001
From: Jean-Marc Lasgouttes <lasgouttes@lyx.org>
Date: Sun, 17 Jul 2022 20:10:53 +0200
Subject: [PATCH] Add proper extension as needed in Save as and Export

Introduce the new FileName method ensureExtension, which does the following:
* if the extension is already correct (in a case-insensitive way), do nothing.
* if it is not correct, add the extension to the file name.

This is different from changeExtension that will fail in a case where
the file contains dots, but not a real extension, like newfile2.1.

Use this new method in renameBuffer() and exportBufferAs().

Fixes bug #11008.
---
 src/frontends/qt/GuiView.cpp |  8 ++++----
 src/support/FileName.cpp     | 13 +++++++++++++
 src/support/FileName.h       |  3 +++
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/frontends/qt/GuiView.cpp b/src/frontends/qt/GuiView.cpp
index 24969c2112..8f6bf07115 100644
--- a/src/frontends/qt/GuiView.cpp
+++ b/src/frontends/qt/GuiView.cpp
@@ -3080,8 +3080,7 @@ bool GuiView::renameBuffer(Buffer & b, docstring const & newname, RenameKind kin
 		dlg.setButton1(qt_("D&ocuments"), toqstr(lyxrc.document_path));
 		dlg.setButton2(qt_("&Templates"), toqstr(lyxrc.template_path));
 
-		if (!isLyXFileName(fname.absFileName()))
-			fname.changeExtension(".lyx");
+		fname.ensureExtension(".lyx");
 
 		string const path = as_template ?
 					getTemplatesPath(b)
@@ -3099,8 +3098,7 @@ bool GuiView::renameBuffer(Buffer & b, docstring const & newname, RenameKind kin
 		if (fname.empty())
 			return false;
 
-		if (!isLyXFileName(fname.absFileName()))
-			fname.changeExtension(".lyx");
+		fname.ensureExtension(".lyx");
 	}
 
 	// fname is now the new Buffer location.
@@ -3248,6 +3246,8 @@ bool GuiView::exportBufferAs(Buffer & b, docstring const & iformat)
 	if (fmt_name.empty() || fname.empty())
 		return false;
 
+	fname.ensureExtension(theFormats().extension(fmt_name));
+
 	// fname is now the new Buffer location.
 	if (fname.exists()) {
 		docstring const file = makeDisplayPath(fname.absFileName(), 30);
diff --git a/src/support/FileName.cpp b/src/support/FileName.cpp
index 8ad7e00fa0..5b494a5ec9 100644
--- a/src/support/FileName.cpp
+++ b/src/support/FileName.cpp
@@ -812,6 +812,19 @@ void FileName::changeExtension(string const & extension)
 }
 
 
+void FileName::ensureExtension(string const & extension)
+{
+	string ext;
+	// Make sure the extension starts with a dot
+	if (!extension.empty() && extension[0] != '.')
+		ext= '.' + extension;
+	else
+		ext = extension;
+	if (!suffixIs(ascii_lowercase(absFileName()), ext))
+		set(absFileName() + ext);
+}
+
+
 docstring const FileName::relPath(string const & path) const
 {
 	// FIXME UNICODE
diff --git a/src/support/FileName.h b/src/support/FileName.h
index 1cf1e730f4..95940a9235 100644
--- a/src/support/FileName.h
+++ b/src/support/FileName.h
@@ -177,6 +177,9 @@ public:
 	*/
 	void changeExtension(std::string const & extension);
 
+	/// Add extension to the file name if it is not already there
+	void ensureExtension(std::string const & extension);
+
 	static FileName fromFilesystemEncoding(std::string const & name);
 
 	/// get the current working directory
-- 
2.39.5