[LyX/master] Do not allow the manual insertion of a directory (without filename) into the import dialog and thus prevent an assertion.

[Richard Heck]

commit df1dbe28ce8b1a095ec9b9de92a1dc697c015c28
Author: Juergen Spitzmueller <sp...@lyx.org>
Date:   Sun Mar 23 13:31:21 2014 +0100

    Do not allow the manual insertion of a directory (without filename) into 
the import dialog and thus prevent an assertion.
    
    Fixes: #7437

diff --git a/src/frontends/qt4/GuiView.cpp b/src/frontends/qt4/GuiView.cpp
index 4a4ab00..22681f1 100644
--- a/src/frontends/qt4/GuiView.cpp
+++ b/src/frontends/qt4/GuiView.cpp
@@ -2121,6 +2121,18 @@ void GuiView::importDocument(string const & argument)
        // get absolute path of file
        FileName const fullname(support::makeAbsPath(filename));
 
+       // Can happen if the user entered a path into the dialog
+       // (see bug #7437)
+       if (fullname.onlyFileName().empty()) {
+               docstring msg = bformat(_("The file name '%1$s' is invalid!\n"
+                                         "Aborting import."),
+                                       from_utf8(fullname.absFileName()));
+               frontend::Alert::error(_("File name error"), msg);
+               message(_("Canceled."));
+               return;
+       }
+
+
        FileName const lyxfile(support::changeExtension(fullname.absFileName(), 
".lyx"));
 
        // Check if the document already is open