[LyX/2.3.x] Re-enable input of non-LyX files (e.g., tex, pgf) (#12056)

[Juergen Spitzmueller]

commit 17e4f325f3d216591ab519309e5e044c7e319e33
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Mon Dec 28 09:58:30 2020 +0100

    Re-enable input of non-LyX files (e.g., tex, pgf) (#12056)
    
    This amends [a385b7dc2b58/lyxgit]
    
    (cherry picked from commit 2af8e661a3a7652f31bbef4890a4b9290bf0febd)
---
 src/frontends/qt4/GuiInclude.cpp |   11 +++++++----
 status.23x                       |    2 ++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/frontends/qt4/GuiInclude.cpp b/src/frontends/qt4/GuiInclude.cpp
index d713ef2..5dc776c 100644
--- a/src/frontends/qt4/GuiInclude.cpp
+++ b/src/frontends/qt4/GuiInclude.cpp
@@ -317,14 +317,17 @@ bool GuiInclude::isValid()
 		okPB->setText(qt_("&OK"));
 		return true;
 	}
+
+	string const bpath = buffer().filePath();
+	// Path might be relative to current Buffer, so make absolute
+	FileName const absfname = support::makeAbsPath(fromqstr(fname), bpath);
+
 	// Do we have a LyX filename?
 	if (!isLyXFileName(fromqstr(fname))) {
 		okPB->setText(qt_("&OK"));
-		return false;
+		return absfname.exists();
 	}
-	string const bpath = buffer().filePath();
-	// Path might be relative to current Buffer, so make absolute
-	FileName const absfname = support::makeAbsPath(fromqstr(fname), bpath);
+
 	// Set OK button text according to whether file already exists
 	okPB->setText(absfname.exists() ? qt_("&OK") : qt_("&Create"));
 	// enable edit button iff file is open in some Buffer
diff --git a/status.23x b/status.23x
index d9a0b10..3fbb0d7 100644
--- a/status.23x
+++ b/status.23x
@@ -53,6 +53,8 @@ What's new
 
 * USER INTERFACE
 
+- Re-enable input of non-LyX files (e.g., tex, pgf) (bug 12056).
+
 - Fix problem with display of menus on Gnome Wayland (bug 11746).
 
 - Improve error message for VCS file registration when RCS package